Bad radiator valve? Replacement?


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Old 01-18-11, 09:40 AM
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Bad radiator valve? Replacement?

Hello,

A few questions here.

I have hot water radiators throughout my house on what I think is a parallel feed system. A few of my radiators seem to not be getting really hot or sometimes not hot at all. Sometimes the supply line is hot up until the valve and sometimes it is not. Im also trying to "balance" the system so the radiators further away from the boiler operate better. A few of the valves when i first moved in seems seized and i cracked them loose with a pair of channel locks. I have at least one valve that doesnt seem to stop turning no matter which way you turn it. And yes the valve shaft is actually spinning its not just a loose or broken cap.

Ive seen similar valves at home depot for like $15 a piece. How hard are these to replace? I can see that its just a standard thread on type but what about the system being pressurized. I assume I turn the boiler off. Do I need to drain it? How about all of the water in the pipes? Am i going to have to deal with water gushing out of the radiator?

Can I rebuild the valves?

Thanks for any advice and if you need pictures of the valves i can prob snap a few pics in a couple of hours here.

Thanks!
 
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Old 01-18-11, 10:27 AM
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The valve may have just broke open and you may not need to change it. You did say hot water and its not steam correct? You may just have air in the system. Some info is needed to better help you.

Did you bleed the air out of the radiators?
What is the make and model boiler?
What is the temp and pressure reading on the boiler gauge?
How many zones?

Mike NJ
 
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Old 01-20-11, 07:38 AM
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Sorry about the delay! I though I had instant e-mail notification on and I didnt see any replies.

-The boiler is a Weil Mclain WTGO boiler. I can get the exact model number in the evening for you. It is setup with the tankless hot water coil for domestic hot water. Is this a poor setup? I do have natural gas line feed and hot water heaters are cheap.

- The boiler is hot water as it produces hot water for my well hot water supply and water comes out of the bleed valves on the radiators.

- I bled the radiators at the beginning of the winter and didnt really get any air coming out of them from what i remember but i can certainly go around and do it again to be sure. Should I start with a specific radiator or that doesn't really matter?

- I will look at the temp/pressure gauge tonight and give you accurate readings but the last time I looked at it I remember seeing 12-15psi when the boiler isnt running and 20psi when it is running... i think. As for temp it seems to sit at a 220 when its just sitting and no heat or hot water is being called for. When there is a heat call the temp will go down to 160-180 i think and the boiler runs the entire time.

-one zone, parallel feed system

Thanks for your response!
 
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Old 01-20-11, 09:24 AM
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Your pressure seems good but the temp is way too hot. Check the settings in the aquastat. You should have a hi/lo/diff. What are they set for? Should be HI 180 LO 150 and diff 20. Try bleeding the radiators and start with the highest and farthest an work your way back.

Take pics of your whole system at different angles and close ups of controls ect... We may see something. Post the pics to a place like photobucket and past the URL here.

Mike NJ
 
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Old 01-20-11, 09:52 AM
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If the 220 that you are seeing on the gauge occurs AFTER a heat call, after the burner and circulators have shut down, it may be what we call 'heat soak'. This is when the heat that is trapped in the cast iron of the boiler transfers to the water. With no circulation occurring the temp can go up to 220... on the other hand, if you see 220 when the boiler is running, there is reason for concern.

The LOW setting that Mike mentioned may be lower... 140 should be fine... 130 usually gets a bit 'iffy' on providing enough hot water. The idea with that control is to run it as low as possible that is consistent with adequate hot water in the home. The suggestion for 20 diff is good.
 
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Old 01-20-11, 02:55 PM
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Ok So i was able to take a bunch of pictures. Ive posted them below. The link to the album is also here in case you want to see larger versions.

Boiler pictures by ethan169 - Photobucket

The picture of the pressure/temp gauge is while the furnace is running. So it started out at like 195 deg F and then dropped to 180 and became stable. The pressure looks like its around 15psi during operation. After about 25 min of the completion of the cycle i saw 220F and still 15psi. I assume this is indeed heat soak.

My aquastat settings are 190 high, 175 low and 15 diff.

The feed and return lines for the whole system just look weird to me. Its an old house so im sure its been retrofitted many times. house is built in 1910. You can see in some of those pictures the two large parallel feed and return lines. This supply water to most of the radiators except for a select few. There is a few tees by the boiler where a line is fed to the kitchen with older cast pipes and then so copper pipes head in parallel to the upstairs bathroom which was more recently redone. These pipes have foam insulation on them as do most of the pipes.

What do you think?



















 

Last edited by NJT; 01-20-11 at 04:21 PM.
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Old 01-20-11, 03:16 PM
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Did you set the low down to 140F????
Set the Hi to 180F
Set diff to 20.
The differential does not mean what you set the high and low difference at. The HI/LO should be at least 20 degrees apart.

Now I see the circ and I might think you need more head pressure to get flow through the bigger pipes.

Hopefully Trooper will take over and assist since I am not sure. The boiler is still too large I think, and if it were me I would do a repipe with copper. And since you have a basement replace with copperfin baseboard and get rid of the radiators.

Mike NJ
 
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Old 01-20-11, 03:51 PM
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Yer doin' fine Mike! you don't need me... but I've always gotta pitch my pennies in...

Ethan, first thing... you are spending a fortune on fuel keeping that LOW setting at 175! Not only that, but I don't see a TEMPERING VALVE on the domestic hot water... and this means that the potential for 175░ and even HOTTER (as hot as 220! do you want to stick your hand in boiling water!?) water at the taps is very real, and DANGEROUS!

If you look carefully at the white block thingy in your aquastat, you will see that it says to NEVER SET THE LOW CLOSER THAN 20░ FROM THE HIGH, which Mike has already mentioned. Erratic circulator operation could result. In some cases, the circulator will not run at all.

So please,

Dset the low down to 140F
Set the Hi to 180F
Set diff to 20.
If you do find that you don't have enough hot water, you can raise the LOW up to 150, but please, no higher than that. Tremendous waste of fuel and that much more dangerous. With your setting, if you don't have a tempering valve, ANY setting is dangerous because if you draw hot water when there is a heat call, the potential exists for tap water to come out at 180 or higher... DANGEROUS! did I mention that this is DANGEROUS?

There may in fact be a tempering valve somewhere not visible in the pics though... but even so, why waste all that fuel?
 
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Old 01-20-11, 04:03 PM
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I would never suggest getting rid of radiators though...
 
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Old 01-20-11, 04:09 PM
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Ok guys thanks for the responses!

I bought the place in June and havent touched the settings on the aquastat. NJ Trooper if you remember you actually helped me repair this exact aquastat a few months ago. It had a few bad solder joints causing the relay to chatter and not start the boiler properly. Anyway I will change to your recommended settings now.

NJ Trooper Im assuming a tampering valve is similar if not the same as an anti scald valve? If so there is one right where the line comes out of the domestic hot water coil. It has a cold water line running to it. and looks like it mixes hot and cold. You can see the knob to it in the first picture of the Aqustat in the lower right hand corner. I must say i do still get super hot temps from the sinks when running on just hot water. But the shower will not always get this hot. Especially now in the winter time. I have one of those single handle shower knobs and i almost always have to have it on all the way hot to get a warm shower then usually starts out decent hot temp then cools off then after a while gets hot again. I keep my house pretty cool so the furnace only runs for 30 min in the morning and i try to avoid taking a shower at this time as the hot water is even worse.

What about the pressure issue? Do i need a larger circ pump? Mike mentioned the boiler is too large?

I really dont mind the radiators as they seem to hold a tremendous amount of heat. My furnace only runs twice daily to heat the home. I have it come on in the morning for 30 min to heat up to 60 from 55 and once at night to 60 from 55 the night cycle usually takes anywhere from 15 min to 45 min. It usually over shoots and get up to 62 and eventually settles to 58 by 11 when the setting goes back to 55.
 
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Old 01-20-11, 04:10 PM
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Trooper what do you think about that circ and the 3" pipes. Is it to small? Plus you see how the return ties in iron and copper? The whole piping seems like it does not work well. I would think alot of oil is being used. I think it would be better to zone it and cut out the 3" and replace with copper and copper baseboard.

Or What can he do with what he has? I would say a larger circ at least. If the return comes back to one then the feed probably splits at the boiler and posible could be zoned.

I know his question was about a valve though and we are suggesting he spend $thousands to upgrade....LOL

Mike NJ
 
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Old 01-20-11, 04:16 PM
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Based on what I see in the pics, you may in fact want to leave the HIGH setting at 190...

I think if this were my system, I would seriously consider some re-piping... I would do something like Figure 13 in this manual (I believe your boiler is a Series 1)

http://www.weil-mclain.com/en/multim...wgo1manual.pdf

Just ignore the zone valves...

The idea is that with a large water volume system such as yours, you need to move more water through the radiators... and less water through the boiler. With an arrangement such as fig 13, you can control the flow through the boiler so it will get up to temperature, and also be able to select a large enough pump to keep the flow up in the system... note that there are TWO pumps in that diagram.
 
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Old 01-20-11, 04:18 PM
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By the way, it does appear that the pressure in your boiler is low... it looks like 12 PSI at 180 on the gauge pic... and that's too low. ONLY IF the gauge is to be believed.

 
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Old 01-20-11, 04:22 PM
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You mean figure 12 Trooper???

Mike NJ
 
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Old 01-20-11, 04:24 PM
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I'm just posting away here and not refreshing! I just noticed that you guys have both replied... I'll be back to this in a bit...
 
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Old 01-20-11, 04:35 PM
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No problem.

How would I go about verifying the gauge accuracy?

also i dont really understand the piping diagrams. Is it fig 12 or 13? You mentioned to ignore the zone valves... I think i need to look at it a little harder and read before it and possibly check out the legend lol.

What pressure should it be at? I feel like i saw it at around 20psi when it was running the other day..

Im also a little confused about the aquastat settings. The low and diff are ok? but i should have the hi at 190? It was at 195 i believe. Ill have to look at the pic. Whats the reasoning? I mean the temp the way it was seemed ok. I do agree about the low limit. It would kick on quite a bit in the summer time. although the amount of oil being used was less then the amount on natural gas used for the hot water heater at my last place..
 
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Old 01-20-11, 04:36 PM
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You mean figure 12 Trooper???
No... they are almost the same... but 13 shows a single pump running the primary system loop... I think it could still be run as a single zone, two parallel loops, as long as the flow was adequate in the system, so just ignore the zone valves.
 
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Old 01-20-11, 04:48 PM
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Trooper in post #12 you said notice the two pumps, thats why I thought you meant figure 12. But we are talking about figure 13.

Ethan if you are using less oil then your gas HWH at your other place I would say dont touch anything, but I find it hard to believe.

I guess figure 13 would be alot less pipe work then ripping everything out.



Mike NJ
 
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Old 01-20-11, 04:57 PM
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The low and diff are ok?
NO. TURN THE LOW DOWN TO 140 and see how that goes with the hot water. TURN THE DIFF TO 20.

If 140 makes your hot water situation impossible, go up to 150... or even 160 if you insist... but keep the LOW 20 below the HIGH at all times!

I see that you have a tempering valve... that's good, it should be set to 120-125.
 
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Old 01-20-11, 05:00 PM
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Well i think it depends on the price of both fuels. Our gas bill was usually $40 a month and this was just for a HWH and a gas stove.

I filled the tank up about 4-5 months ago. its now between 1/2 and 1/4 this is a standard 275 gallon. So i take 275*0.375=103gallons used to date. 103*$2.20per gallon = $225 (this was the price i paid at the time which admittedly was super cheap and is now higher) 225/5 = 45 per month. This is with heating the house since mid December. The oil level is going down much faster now that the burners is being summoned to produce hot water for the heating system. So i guess now that I look at it it not that much cheaper. I guess you could take into consideration that my last place was just an apt with one bathroom and this is a house with 3 bathrooms 1 shower. Also much more area to heat.

Anyway. Im still looking at the figures. Multiple zones would be nice. Im just not looking into spending thousands on the heating system right now. Id like to do as much myself as possible. But the pipping does seem to be cobbed. I just dont want to cob it more..
 
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Old 01-20-11, 05:04 PM
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Originally Posted by NJ Trooper View Post
NO. TURN THE LOW DOWN TO 140 and see how that goes with the hot water. TURN THE DIFF TO 20.

If 140 makes your hot water situation impossible, go up to 150... or even 160 if you insist... but keep the LOW 20 below the HIGH at all times!

I see that you have a tempering valve... that's good, it should be set to 120-125.
I have already set the Aqustat to 180 140 and 20 like you guys said. You had mentioned turning the high back to 190 though?
 
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Old 01-20-11, 06:20 PM
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I think Trooper said 190 is good because on the large water volume you have in the large pipes higher heat will move better to get to all the radiators.

Mike NJ
 
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Old 01-20-11, 07:00 PM
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The concern with large pipes (high water volume) is boiler condensation.

I don't think a larger pump is needed either. The pump that came with my boiler performs just fine in my system and I have large piping like ethan does.
 
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Old 01-21-11, 06:11 AM
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Ok so i changed the settings last night to:

High 180
Low 140
Diff 20


I kicked the heat up force a heat call... the boiler kicked on and started running. the temp was around 155 or so maybe 160. (it had been off for several hours) the circulator didn't seem to start running until it hit 180 then the temp started to drop noticeably on the gauge. once it got down to 160-165 the circulator stooped running. The gauge started to rise and the circ started again at 180 or so. Seems there s threshold for the circ to run? Im sure this is normal but it seems that its wasting a lot of energy going on and off and what not.

There are two radiators that or teed off of the two main feed and return lines (3") One that is downstairs in the kitchen (right above the boiler) and one upstairs in the bathroom (those are the two copper lines that run parallel with the 3" pipe in the pic (they are insulated with black foam so they appear black.) When the circ stops the pipes going to the kitchen radiator go cold to the touch....weird.... I understand that water is not flowing anymore but there was hot water in there.

I agree that my piping system is setup quite poorly and I do plan to change things. Id like to keep what i can so im not completely redoing the system. I am going to be COMPLETLEY redoing the kitchen as it is the only room that doesn't look like its really been touched. So I may do a cooper baseboard or radiant in floor if its possible to tie it into my system. It would be nice to put ceramic floor and have it nice and toasty in there when i want.

I increased my High to 190 as i feel like it would operate better at this temp as well.

Side note. Do you think its worth it to look into a hot water tank for the domestic system? or a Natural gas hot water heater? They are super cheap. Nice efficient ones are like $500 which is well worth it if its going to save.

Thanks,

Ethan
 
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Old 01-21-11, 09:51 AM
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the circulator didn't seem to start running until it hit 180 then the temp started to drop noticeably on the gauge. once it got down to 160-165 the circulator stooped running.
When I get a chance this evening if I have time I'm going to revisit and read through the whole thread again... there seem to be some unanswered questions and possibly some misconceptions... we'll work on that.

In response to the above questions about the aquastat, what you are describing is completely inconsistent with the settings that you are now running.

With the LOW at 140 and the DIFF at 20 what you SHOULD see is the circulator only stopping when the boiler temp gets down to 130 ! and the circ should start running again at 150 ... so there seems to be a problem with your aquastat.

Do you think its worth it to look into a hot water tank for the domestic system? or a Natural gas hot water heater?
Yes, absolutely. Anything is better than the 'thankless' coil system that you are now using.

AND, if you are currently having trouble with the existing aquastat, this would be the time to change to something like an L7224U because when you abandon the coil in the boiler you are going to want to switch the boiler to COLD START. No longer will there be reason to keep the boiler warm 24/7 ...

L7224U1002 - Honeywell L7224U1002 - 120 Vac Oil Electronic Aquastat
 
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Old 01-22-11, 04:34 PM
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Any update?

My pressure does seem to still be low. Of course i have no idea what it should be set at. Also my aquastat seems to not be controlling things correctly?

What is the proper operation with the suggested settings? 180 140 and 20 for diff.

Im still a little unsure how the diff is supposed to work. Interestingly enough the whole system seemed to work better at the original settings before i touched it. Which if i remember were 195 175 and 15 diff. With those settings i dont remember the circ pump going on and off like it does now....

Thanks for any replies!
 
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Old 01-23-11, 09:42 AM
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I'm busy this weekend, trying to get quick updates to some of these threads...

I believe your aquastat is crapped out. If it's acting the way it's acting, something is definitely wrong with it. If it worked better the way it was it's because those hacked settings were allowing the pump to run sooner.

You can't do anything more until you determine if the aquastat is bad (I believe that it is) and have that replaced. Until that time there is no point in confusing the issue with answers to the other questions. I mean, if yer stuck with a flat tire, what's the point in asking about the headlights?

By the way, the L7224U can be used on EITHER a cold OR warm start by a few switch presses to set it up. So, if you do replace with that, you can use the same unit NOW with your existing hot water system, AND later with a different water heater.
 
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Old 01-24-11, 05:05 AM
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No problem Trooper. I appreciate your help on this. In the mean time im going to buy the newer aquastat. You most likely right in saying miine is on the fritz. This might also explain why it takes forever for the hot water to reach the radiators at the end of my system. Which by the way solve my initial problem of a "broken valve" now that its been a little bit colder outside ive had the heat come on for a little bit longer now to be sure that no pipes are freezing and to make temps bareable heh. So eventually after enough circ cycles the water reaches the end of the system and this radiator gets hot!

Hopefully Ill have the new one in the middle of this week or so.

Thanks,

Ethan
 
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Old 01-24-11, 09:47 AM
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My pressure does seem to still be low. Of course i have no idea what it should be set at.
And I always say: never trust a boiler gauge. So, it only appears to be low on a gauge of unknown accuracy.

The pressure in the system should always be a miminum of 12 PSI when the boiler is COLD... room temperature. In some cases, such as a 3 story home, the pressure would need to be a few PSI higher when cold.

As the water is heated, and expanded, the pressure will be higher, it could go as high as perhaps 25 without problem, but in general, 18-20 max when the system is HOT (as yours is showing on the gauge pic) ... and this maximum pressure is controlled by the size and condition of the expansion tank.
 
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Old 01-24-11, 10:34 AM
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Originally Posted by NJ Trooper View Post
And I always say: never trust a boiler gauge. So, it only appears to be low on a gauge of unknown accuracy.
Understood. A new gauge cant be too expensive right? I assume its relativley easy to replace? Or do i have to drain the entire system? as removing the gauge will open the system up? Also the new aquastat L7224U1002 has a temp readout correct? Should be more accurate then the gauge I assume?

Thanks,

Ethan
 
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Old 01-24-11, 03:07 PM
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Before changing the gauge, you can make one up with a few fittings and screw it on to one of the boiler drains... open drain, read pressure. For about $10 at HD or Lowes you can get one of these:


image courtesy plumbersurplus.com

The gauge is useless for low pressure boiler work though, but the fitting is worth the bucks I think... So stop by a plumbing or swimming pool supply on the way home and pick up a 0-30 or 0-50 PSI gauge and replace the one it comes with.

Chances are that you will have to drain the system to replace the gauge. You may not have to drain if you are adventurous and let the boiler cool off, and only drop the pressure to zero, and have the new gauge ready to screw in, you can probably change it without getting too wet if you work fast and have a helper with a thumb to cover the hole ready... make sure you cover the burner and controls with plastic... but to do this in the winter is not the best idea.

L7224U1002 has a temp readout correct? Should be more accurate then the gauge I assume?
Affirmative, but we're not talking about temperature, rather PRESSURE, which the aquastat does not have a readout of.
 
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Old 01-27-11, 02:41 PM
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Ok so received the new aquastat and installed it. The old aqusatat might have actually been ok i just dont think the capilary tube was inserted all the way into the well and my temp gauge is off on the boiler so it was difficult to diagnose. Im glad i got the newer version though with the thermocouple and digital readout.

Settings from what i remember.
Hi 185
Hi dif 20
Low 145
Low diff 15

Here is what i think is happening. A heat call is seen at the aquastat and the circulator starts. A few seconds later the burner starts as the temp is below the hi minus the differential usually or it gets there pretty qucik from all of the cold water entering the boiler from the return piping. Since i have these large 3" and 4" galvanized pipes for feed and return they hold a great amount of water in them that is usually cold when a heat call is first had. (I keep my house pretty cold so most of the day is spent with no heat really required) The circulator pumps the hot water from the boiler out into the feed line and radiators as it is drawing cold water from the return line that is cold when the boiler temp drops below the low - low differential the circulator stops and heats the "fresh load" of water. When it reaches the low limit the circ starts again. So this cycle keeps happening. Because of this cycling it takes a while for the hot water to reach the radiators towards the end of the system. Is my boiler too small for my application?

Would it be beneficial to replace the feed and return lines with some smaller lines? Maybe even pex to make the install easy and cheaper? Like 1" PEX or 1 1/2" maybe? I could do copper relativley easy too i guess since its a straight shot and i would just need tees coming off that would feed into the threaded pipes that go to each radiator. Were the boilers back in the day so big that they held enough water to keep those pipes hot?

Would keeping the temp in the house up around 60 all day be better? Keeping the water in the pipes warmer most of the day? This would require more cycles during the day i would assume. Im ok with the time it takes for the house to heat to temp in the morning and evening im more concerned with oil consumption. Whats the best way to go about this?

Im working on getting a pressure gauge hooked up to a boiler valve to see what the actual pressure is in the system as im sure the one on the boiler is faulty. I know the temp part of the dual gauge is off for sure. It reads 180 when its really 145-150 or so. So that 220 i was seeing a while back was most likely a lot less. The way everything is set up now the boiler never really see the hi limit.

Thanks for any advice guys!

Ethan

p.s. installation of the new aquastat was super easy. Direct replacement pretty much.
 
  #33  
Old 01-27-11, 03:28 PM
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I think you need to change the low to keep the boiler at a higher temp and the circ on more. The minumum spread from hi to low is 20 degrees. Try low 155F. Also I know there will be a agrument about the diff but I am not convinced about 20. I think 10 diif may be better since the diff only works for the low and has nothing to do with the hi. You want the burner to come on as soon as possible because you have cold water coming in.

I would set 190HI 170 LO and 10 DIFF. In the summer I would do LO 130. The HI goes to sleep during the summer.

Guide to Setting & Wiring Heating System Boiler Aquastat Controls, how to set the HI limit LO limit and DIFFerential dials on controls like the Honeywell R8182D Combination Control Aquastat

Mike NJ
 
  #34  
Old 01-27-11, 03:38 PM
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This is why I say to never trust them damn gauges... it does sound as though the old a'stat might have been doing what it was supposed to be doing, and it only looked bad because of the temp gauge being off.

Is my boiler too small for my application?
Highly doubtful. I would fully expect the behavior you are describing from your system.

I still believe that the best thing you could do, cost vs. benefit, would be to install a BOILER BYPASS line. It would be relatively easy to do on your system.

It would involve cutting into the return line at the lower left and installing a TEE, pointing up. Move the green flow check valve to the section of pipe that heads back toward the wall on the supply side. Move the pump to where the flow check is now (although I'm not crazy about it being above the burner where it could leak onto it, so if there's enough room on the pipe on the side, it could go there as well, with the flow check... OR ditch the flow check and install a NEW PUMP with an internal flow check). Come out of the boiler into a good quality GLOBE valve. Then a TEE, pointing to the left. Run a full size bypass (is that copper 1-1/4" ?) between the tee on the return and the tee on the supply, with another good quality globe valve in the bypass line.

With this arrangement, you can adjust the valve on the supply out of the boiler to throttle the flow through the boiler down. The boiler will get hotter faster, and won't be as affected by the sudden surges of cold water coming back in the return. Yes, the return will still be cold, but there will be much less of it flowing through the boiler.

The valve on the bypass line will likely be always full open, and you could actually use a full port ball valve there. Ball valves aren't really recommended for throttling applications, and if you don't have to throttle the bypass, a ball valve would be acceptable. In SOME cases though, you may have to throttle the bypass, but not likely.

The net outcome of this will be that the boiler will be 'injecting' heated water into the system, and will be happier because it won't be subjected to that huge volume of cold water slamming into it. The AVERAGE temp in the boiler will be increased because the DELTA TEE (temperature difference) between the supply and the return will increase. While the return is staying at the same temp, the supply will be hotter faster.

A somewhat costlier option would be to go with a PRIMARY/SECONDARY arrangement. Sorta the same idea, but somewhat more control. It would involve control rewiring and such because there would be a second pump involved. The BIG advantage to this approach with your system would be that the pump that moves the water through the radiators will ALWAYS run when there is a heat call. This will GREATLY improve the 'balance' of the heating system because the heat will move out to ALL the radiators as the water gets warmer, with no interruptions.

My furnace only runs twice daily to heat the home. I have it come on in the morning for 30 min to heat up to 60 from 55 and once at night to 60 from 55 the night cycle usually takes anywhere from 15 min to 45 min.
With this run time, say an hour and fifteen minutes, I would think that you can't possibly be using that much oil for HEATING. If this is actual BURNER run time, and your nozzle is let's say 1.25 Gall / Hour, that's only about a GALLON AND A HALF A DAY... which is NOTHING to heat a home! Works out to something like 10,000 BTU / HOUR. I somehow think that you are underestimating the time that the boiler is running.

That said, let's not forget that you are also keeping the boiler HOT to heat your domestic... so there must be run time in between for that purpose.

more...
 
  #35  
Old 01-27-11, 04:04 PM
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Aquastat settings:

I would increase the LOW DIFF to 20.

With the HIGH DIFF at 20 you might have less 'short cycling' once the water warms up in the system, so it's probably a good choice... but you said the boiler doesn't normally hit the high limit anyway? so the point is probably moot.
 
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Old 01-31-11, 01:49 PM
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Ok so I think you may be right by saying the best bet is to do a boiler bypas valve / loop.

Ok let me see if i understand how this setup would be most easily done. You say to install a TEE at the return line at the bottom left of the boiler facing up? Do you mean to say install the tee in the RETURN line facing up on the bottom right back of the boiler? Then a TEE on the SUPPLY line facing down towards this other TEE in the place of the 90 degree elbow that is present now? This would give a pretty direct shot between the two tees. I feel like adding the TEE right at the inlet to the boiler for the return line would require quite a bit more piping which would just be more expensive and promote more heat loss in the copper...?

To do this im assuming I would have to drain my system right? Especially to get the pipes dry so I can sweat them without problems. How would i even go about doing that?

Also what would you recommend as a good quality "globe" valve for this throttling application?

I can try to do this on a warm weekend when i dont really need the heat during the day.

Thanks!
 
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Old 01-31-11, 03:43 PM
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Yes, you most definitely would have to pretty much completely drain the boiler. And it doesn't appear that you have valves in either the supply or return lines which you can close in order to isolate the system from the boiler. Those would be nice because it would mean that you wouldn't have to drain the boiler AND the entire system... doesn't look as if you have a choice though. You might consider adding some valves in order to do so... if you ever need to again in the future for some reason.

BUT: I would strongly discourage you from doing this in the middle of the winter ! It is NOT a good idea.

I'm not sure if you're following my description, or if I'm following yours, so let me see if I can scribble on one of your pics to give you a better idea of what's involved.
 
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Old 01-31-11, 04:38 PM
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OK, this is a really bad, quick and dirty hack job, but I think it should be clear enough as to give you an idea of what you might want to do.

Note that one of the valves is directly at the boiler supply out... the other is on the bypass line. I've placed a couple (optional) isolation valves also.

Remember, this is CONCEPT ONLY, your mileage can vary.



It would not be a bad idea to also add isolation flanges to the new pump so you can change it if need be without draining the system. If you do this, those valves can act as the isolation valve up on the supply line...

There's probably a number of other suggestions that you will get, such as adding a decent air removal device such as a SpiroVent... but this is a start.
 
 

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