Boiler with summer winter hook up not producing hot water!

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  #1  
Old 01-14-10, 09:23 AM
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Boiler with summer winter hook up not producing hot water!

As I know it, our boiler works well. We get heat in the house and all is good. The boiler is 7 years old and is maintained once a year.

We don't have a water heater for domestic use so all of our hot water comes from the boiler. We have hot water heat along the baseboards.

Every morning, it is impossible to get more than 5 minutes of hot water out of the shower. I was told by a plumber friend (very experienced) that doing an acid wash through the grids (?) would fix the problem but might shorten the life of the boiler.

I am working on adding a master bath and will most likely add a hot water heater for domestic use but that is a couple of months away.

The shower gets hot in the afternoon and for a good while at night, but in the mornings it is impossible. Suggestions? The kids are getting restless!
 
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Old 01-14-10, 01:55 PM
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As usual, you may want to post some pics of your installation.
There may be a defective aquastat preventing the boiler from reaching the proper temperature for DHW generation alone.

Do you set back your thermostat at night ?
 
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Old 01-14-10, 06:42 PM
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I might be way out in left field but my guess is you turn the thermostat down at night and have cast iron radiation. Please tell me I am wrong.
 
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Old 01-14-10, 06:47 PM
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Yeah, you're wrong. We don't touch the thermostat... it stays around 68 all winter. And the heat is ran through the copper pipes with the tin squares.

i'll post pics tomorrow
 
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Old 01-14-10, 07:25 PM
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Using a domestic hot water coil is not a very practical way of making hot water. As soon as the oxides coat the outside of the coil, the rating goes out the window. A 5gpm coil which would have trouble making 4 gpm on a good day will make about 2.5 after a few years in service. You can compensate for some of the loss by making sure your water pressure is around 50 psi and that you are using a water saver (2.75 gpm max) shower head. Once that doesn't cut it, you will end up with a storage tank or an indirect water heater. I would not recommend an electric water heater. You will experience substantial savings in the non-heating months after relieving the boiler of the instantaneous requirement of producing hot water. Especially if you install the right temperature control on the boiler at the same time.

Ken
 
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Old 01-14-10, 08:01 PM
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Whew I'm glad you don't turn back the t-stat at night and have cast iron radiators. What are the control settings, is there some type of mixing valve either automatic or manual?
How many thermostats in the home?
 
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Old 01-15-10, 06:41 AM
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There is only one thermostat in the whole house! We live in a neighborhood that was built about 45-50 years ago. There are a lot of units and they are all single family homes (about 3200 sqft.) They are big houses for the period they were built and of course had several options. One of the options was a master bath. So some homes have 1 1/2 baths, others have 2 1/2 baths. Mine only has 1 1/2, but the plumbing was actually ran when initially built into a sort of an alcove in the master bedroom ( I found it when I took down the kitchen ceiling to replace) so it exists to add the master bath (meant for a stand up shower, toilet, and sink).

I am putting windows and siding in within the next month then working on the master bath sometime mid spring. I tell you this because the MY house has only one zone for heating. It's a continuous loop ran off of one thermostat for both upstairs and down stairs.

My neighbors, who I just redid their whole kitchen, has their house zoned for upstairs and downstairs, AND the previous owner also installed a hot water heater for domestic hot water.

I think I am going to go that way when I redo the master bath in a few months. The thermostat is a Hunter Energy Monitor Plus II. It's digital with an LCD display. We never use the timer on it. We just set it at 68 and leave it for the winter. The house is comfortable and we always get heat. Except for times in the shower.

I think field answered my question. The pressure is at 50 and the temp is at 160 degrees.

I was thinking of doing that acid wash, but if it really does lessen the life span of the boiler, I think I'll just make the fam suffer for another 2 months. It's not like they aren't used to it. By then, I could install the new hot water heater (gas) and solve most problems.

When I do the master bath and the new hot water heater, would it be wise to add another zone to the boiler for upstairs? Would I have to replace the boiler anyway at that time because I will no longer be using it for domestic hot? Or will the coil just come off of the boiler, or can it stay? Aside from doing the usual plumbing work (faucets, toilets, supply, etc.) I'm afraid I'm not educated in the nomenclature of boilers, hot water heaters, etc...
 
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Old 01-15-10, 06:59 AM
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There will be no need to replace the boiler if you stop using the coil. Just let the tappings open and it will dry out in a couple of hours. Turn down the low setting on your temperature control to let the boiler go to a lower temperature between cycles. Or replace the control with Becketts new Aquasmart controller. That has the heat manager control built in and it allows you to set the low lmit at 100 degrees or turn it off all together if you choose. Zoning is always a good thing as far as comfort is concerned. Depending on how the piping is installed, it may be easy and it may be hard. The acid flush will not shorten the lifespan of your boiler by any amount that you will ever see. If you flushed it 100 times, maybe but I have boilers whose coils we flushed at least 15 times and the coils are still working. I have seen boilers whose coils have never been flushed and they leak so go figure.

Ken
 
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Old 01-15-10, 07:35 AM
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Awesome stuff Ken! Thanks for your help.

I will most likely hire a professional to install the water heater and rezone. I'm just not comfortable enough to go that far, realizing that it may or may not be easy. I would assume that there is the possibility of having to add some additional piping or even having to run a whole new system throughout the new zone. Something I may consider given the fact that I will likely have to move one of the sections of heater runs where I will be building he new bath. Add to that that the original pipes that are running throughout the house look less than stable, especially near the joints.

Do you think that would be the right thing to do given the fact that I am going so far into my renovation anyway? Or is it a little overkill? We have not experienced any leaks to date.

There's a lot I want to do and a lot I need to do. I can absorb the cost because I will be doing the whole bath myself.


I will however do the flush now as I was shown how to do that. Simple enough.

Thnx again!
 
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Old 01-15-10, 07:56 AM
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Originally Posted by riggstad View Post
Every morning, it is impossible to get more than 5 minutes of hot water out of the shower. I was told by a plumber friend (very experienced) that doing an acid wash through the grids (?) would fix the problem but might shorten the life of the boiler.
I think that before spending any money I would look in another area.

The Boiler is probably still carrying Aquastat settings that were appropriate for the prior Owner. They may not have placed much of a concentrated demand for hot water on the system as does your family. It may be just a matter of life styles, and whoever had the house earlier didn't demand that much hot water in as short a period of time as your family. You need the Burner to respond at an earlier (higher temp) point so as to provide continuous hot water.

I would check the Boiler's Low Limit Setting and the Low Limit Differential. If the Boiler is only 7 years old, the Information of the Aquastat should still be around. Your Plumber should be able to tell you how to make a few adjustments to test this theory, and then experiment until the Aquastat is adjusted to reflect the needs of the current occupants - you and your kids.

The Low Limit Setting may have to be raised (or the differential lessened) so that the Burner is called on to replenish the hot water earlier than it is now. This way, the human being(s) can complete their shower(s) in comfort. These boilers have been providing continuous hot water for decades . . . . there's no reason why yours can't do the same. And it's both a cheap and a permanent fix.

JMHO.
 

Last edited by Vermont; 01-15-10 at 08:16 AM.
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Old 01-15-10, 08:12 AM
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I think you are right because the previous owners were empty nesters (2 bodies) and I have 5 children (including the wife) so that's 6.

Laundry is running constantly throughout the day and the wife insists on showers everyday for the kids. (all under 12 so it's usually 2 baths and 2 showers even before wife and I get ours).

I guess the demand would far exceed what it was initially set for assuming the previous owner knew to lessen it. Of course it was installed about 2 years before we bought it so the installer would have set the settings and known to set it for 2 people living in the house.

I can't see any controls other than the temp/ pressure gauge. there is a panel that looks like it comes off but I haven't fussed with it yet.

I will take pics and post and see if any of you guys can walk me through adjusting what needs to be adjusted.
 
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Old 01-15-10, 09:00 AM
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Here are some pics

I'm trying to upload three pics I took of the boiler. One is the whole system, the other is a close-up of the valves and such, and the other is of the open panel. It's a peerless cast iron boiler.

if the pics don't upload, you can go to this link and it will take you to flkr and directly to he three pics.




boiler 3 on Flickr - Photo Sharing!

boiler 2 on Flickr - Photo Sharing!

boiler 1 on Flickr - Photo Sharing!
 
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Old 01-15-10, 09:48 AM
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Nice Cat !

Your Aquastat Settings are behind the cover of the grey box saying "Honeywell". One screw loosened allows you to remove the cover and take a peak inside, just to see what the current settings are. The inside of the cover probably has the details on the Aquastat Model Number (and a whole lot more).

Look for the paperwork on this Unit or download it from Honeywell before going any further.

Your Plumber Friend probably has the literature handy. Buy a 6 Pack and call him over for a on-site consultation. Mid winter is not the time to venture into unfamiliar territory without a good guide.
 
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Old 01-15-10, 12:51 PM
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Alright Vermont... I took the cover off and peeked inside. It is a veritable rats nest of wires but nothing looks out of place.

There are two dials. One for high and one for low. the low is set at 160 (which is what the temp reads on the boiler guage), and the hi is set for 190.

I looked up the info on Honeywells site. They didn't have anything to down load but specs on this unit were as follows:

Application High Limit Protection, Low Limit and
Circulation Control

Operating Range, Low Limit (F) 110 F to 220 F adj.

Operating Range, High Limit (F) 130 F to 240 F adj.

Differential Temperature (F) High limit : 10 F fixed;
low limit: 10-25 F adj.

Maximum Safe Operating Pressure (psi) 200 psi on outside of immersion well, 100 psi on capsule if inserted directly.

Is this as easy as turning the "hi" dial to 220 or so? If so do I need to compensate for a higher low as well because of the operating range definitions? I'm totally guessing here.

Thanks for the info!
 
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Old 01-15-10, 12:59 PM
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Have you considered an indirect hot water tank? They will recover faster than a direct fired gas water heater.
 
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Old 01-15-10, 01:28 PM
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Originally Posted by riggstad View Post
Is this as easy as turning the "hi" dial to 220 or so? If so do I need to compensate for a higher low as well because of the operating range definitions? I'm totally guessing here.
No! We don't want any blown PRVs or busted Boilers! Remember, water boils at +212F at Sea Level, and if you're in Philly, you want your High Limit to always stay below that, unless you know for a fact that you can control the additional pressure.

Now's not a good time to guess; but I think you should be concentrating on carefully raising the Low Limit adjustment, and narrowing the Differential.

Now's a good time to call your Plumber Friend and see if he has the literature on the your Model Aquastat. Didn't the former Owners leave you a pile of Literature on all the appliances?

I'm a Real Estate Broker and we always encourage people to gather that stuff up when they initially list a house so that it's readily available for the New Owners.

It may look like a Rat's Nest; but that Cat of yours has probably prevented real rats from taking up residence inside the Aquastat!

Someone else who works with these settings routinely can possible provide some guidance here as well. Remember it's Winter out there! Your system isn't broken . . . . yet. You just want to fine tune it to your Family's needs.
 

Last edited by Vermont; 01-15-10 at 01:45 PM.
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Old 01-15-10, 01:39 PM
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I would not get the 'decades of unlimited hot water' thought too burned into your brain cells because decades ago, people were just happy to have warm water on them for 3 minutes. We are now at the decade of '1 shower head and 2 body sprays and if I could bring in a magazine, I would read that during my hot water massage.' You and your family are obviously not that way, but other people with domestic coil boilers are and they end up very disappointed. I believe you are headed in the right direction and I do agree with drooplug that an indirect could be a good idea. The ability of your boiler to heat water is still very good, just not water in the domestic coil. You could turn up the aquastat to 210 and then when one of your kids opens a faucet, they risk a 3rd degree burn. So rule that out. There should already be a mixing valve on there with the high limit at 180. But a mixing valve can't make the water hotter, only cooler. And sometime they stick and make the water way too cool so they aren't perfect either. But if you install an indirect water heater, you can have thereserve that would be helpful and let the combustion appliance that you already own do the work. Just use an aquastat that is smart enough to maximize your fuel usage year-round.

Ken
 
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Old 01-15-10, 01:59 PM
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So an indirect would be a tank that would be heated by the boiler, but be able to store up to 80 gallons of water?

Could it be that easy?

I think if that's the case we could be in business. I might even not even wait for something of that possibility.
 
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Old 01-15-10, 02:06 PM
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Most indirects are stainless steel tanks with a stainless steel heating coil inside. Usually a 40 gallon indirect is sufficient but you can look over the actual ratings. Be sure to know the net output of your boiler because at the larger sizes, indirects can really suck up the btus. It would be especially appropriate to install that during the same time that you split the house into zones because the indirect gets treated like another zone off of the boiler and you could kill multiple birds with one stone.

Ken
 
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Old 01-15-10, 02:30 PM
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This has all been very helpful. I think my plan of action will be to take my new found understanding to my guy and discuss best case scenarios from temporarily increasing the heat for the rest of the winter to adding the zones and indirect tank.

As soon as I get my plans together I will re-post with some options I am given, and what I think might be the best way to go.
 
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Old 01-15-10, 02:44 PM
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I don't buy the dirty coil idea unless the demand for hot water is less in the afternoon than the AM. A dirty coil reacts the same at all times. It is not better one time than another unless something else changes such as water pressure, thermostat recovery, flow or system water volume to name a few.
I had a job where the guy would run out of hot water in the late evening. I had him put a pressure gage on his system and check at 3 - 4 times a day. The pressure was about 60 psi all day. At about 8 am it would go to 105 psi.
What is the differential setting on the control? You are at 160 on the low setting. If you want more hot water you want to increase the differential not decrease the differential.
 
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Old 01-16-10, 08:25 AM
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Originally Posted by rbeck View Post
If you want more hot water you want to increase the differential not decrease the differential.

By differential I assume you mean the difference between the hi and low setting. That would be hi at 190 and low at 160.

Should it be different? Should I go to 200 and 180? I have to assume it's not that simple.
 
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Old 01-16-10, 08:30 AM
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No... inside your aquastat there are three dials.

HIGH

LOW

DIFF

The HIGH is the high limit for the heating circuit. It will cut off the burner when the limit is reached.

The LOW is the setpoint that the boiler will keep warm (hot) at.

The DIFF is a setting that controls how long the boiler will run when it hits the LOW setting. Set that one to at least 20

And I think it's been mentioned not to set the LOW any closer than 20 to the HIGH.
 
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Old 01-16-10, 08:34 AM
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I'm a little confused... (again!)

Earlier you said that there are TWO dials inside your aquastat?

Look again, there should be three...

If not, please pop the cover off and look at the label inside the cover and tell us what model that is... or, better yet, take another picture!
 
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Old 01-16-10, 08:57 AM
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I got ya! There is a third dial... it was hidden behind all the wires. It says DIFF and is set at 15!

The other settings are 10 20 and 25.

I will set it at 20 for now, but does that setting correlate with the either the hi or the low?

Meaning, is it OK to keep the hi at 190 and the low at 160 after changing the diff to 20 or even 25?
 
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Old 01-16-10, 09:32 AM
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The DIFF works along with the LOW setting. It gets confusing how to explain the working of that, but I think it's easy enough to say that 20 will give a slightly longer run time when hot water is being used, and thus, you might notice slightly more hot water to be used! rbeck usually advocates going all the way to 25... but try 20 first and see if you don't get some improvement.

I would probably turn the 190 down to 180...

I would also usually say to turn the 160 down some, but since you are already complaining about hot water, I'm not going to do that... instead:

A little about water temps, especially in view of the fact that you have children in the home...

With the settings that you have, your system is CAPABLE of supplying 190 water to the taps! Water that hot will peel skin off in seconds... even at temps much lower than that. SEVERE injury can result from water this hot.

Even if the boiler is not at 190 when you draw the hot water, it will still not be lower than 150... and even 150 is very dangerous!

OK, what to do? you are planning on an indirect... that's the right move I believe. But, in the meantime, take a look at your boiler... see that valve with the yellow handle that's between the cold supply to the tankless coil, and the hot out to the house? Even though that type of valve (ball valve) is not recommended for 'throttling' purposes, you CAN try opening that valve just a bit in order to blend some of the cold with the hot before it heads off to the house.

This will help in two ways... first, the water to the house won't be quite as dangerously hot, and second, it will decrease the flow through the coil in the boiler and allow more 'contact time' with the water that does flow through the coil... so even with peak demands, the water coming out of the coil will be slightly hotter before you mix it with that little bit of cold from the bypass.

Even though you are going to be mixing some cold with the hot, you MIGHT find that the net result of this is slightly more hot (enough) water available to the home.

There are thermostatic valves available that do the same thing, but actually CONTROL the temp of the water to the home. If you aren't ready just yet to install that indirect, and are considering boiling out the crud in your coil, you will have to cut those pipes anyhow... you might consider plumbing one of these in at that time...

Taco 5000 series mixing valve

The upside to this is that it will provide safety, extend the output of your coil, AND, when you pipe the indirect, you can re-use this valve at the outlet of the indirect! So it's not wasted $$$.
 
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Old 01-16-10, 09:42 AM
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wife insists on showers everyday for the kids
I would too!

Q: Are your kids spoiled?

A: No, they always smell like that!

ha ha ha ... sorry ... old joke, couldn't resist!
 
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Old 01-16-10, 11:16 AM
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That's awesome advice. I up'd the diff to just past 20 and after a day or two, might even lower the 190 to 180.

the extremely hot temps are normal for this house and I actually installed a single handle faucet when I re did the bath just this past summer. It helps in the sense that the kids know to turn on the water "in the middle" so as not to have to turn on just the hot and risk injury.

I've noticed in the kitchen when turning on just the hot it is ridiculously hot.

I spoke to the plumbing friend and our course of action for next weekend is to clean out that coil and install the taco.

I'll keep you informed of the progress. Thnx everyone for all your help!
 
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Old 01-18-10, 10:00 AM
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Originally Posted by rbeck View Post
Whew I'm glad you don't turn back the t-stat at night and have cast iron radiators.
hi folks! hope it's ok to ask this here rbeck. trying to learn all I can from the forum. Is it just bad to turn your tstat back at night only if you have cast iron radiators?
 
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Old 01-18-10, 03:29 PM
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I don't see why not ask...

Here's my take on setbacks:

If you have a heating system that recovers slowly from a deep setback period, it's probably better to NOT set back as far.

Scorched Hot Air systems recover rather quickly from setbacks, so it's probably OK to go 5 or more degrees. (Although you will still probably notice more 'cycling' of the furnace as it reheats the structure and the furnishings.)

Forced How Water systems take a bit more time to recover, so the setbacks should not be as deep.

If your forced hot water has big ole cast iron radiators, you are probably better off with minimum setback due to the amount of time to recover. Also, systems with large water volumes, and lots of cast iron will tend to cause flue gas condensation for longer periods of time when they are attempting to recover because of the amount of cool return water heading back to the boiler. Systems in this category should ALWAYS have boiler protection built into the piping... (bypass).
 
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Old 01-19-10, 08:43 AM
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thanks trooper!

This stuff is pretty complicated isn't it? The dynamics make your (well at least mine) head spin.

Probably should know this from past discussions on the forum - but I just don't remember. Whenever you get time could you explain how the bypass works?

thanks for your response!
 
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Old 01-19-10, 03:21 PM
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I guess we can kill some time while we're waiting for rigg's report!

Very basically, a bypass does just what it says... bypasses some of the flow.

There are two basic types, BOILER and SYSTEM.

BOILER bypass goes from the supply to the return of the boiler, on the boiler side of the circulator, and reduces the flow through the boiler. This allows the boiler to come to temperature a bit faster... and the difference between the return water and the supply water is increased (called Delta T, or DT). By the boiler getting hot faster, and the increased DT, the AVERAGE temp in the boiler is raised, and condensation is minimized. With a BOILER bypass, you have FULL FLOW in the system, so the heat is still evenly distributed in the home.

SYSTEM bypass also goes from the return to the supply, but on the system side of the circulator pump. This protects the boiler also by routing some of the HOT supply back to the return... and also raising the average temp in the boiler (but the DT is reduced). The drawback to the SYSTEM bypass is that now the flow in the system is reduced, and there can be uneven heating as a result.
 
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Old 01-19-10, 07:33 PM
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Since adjusting the differential, we' have had some success with adding more domestic hot water. It was super cold the last week (abnormally low for our area with it getting into the teens at night and staying below the 20's during the day)

The only difference is that the temps have gotten surprisingly warmer since I made the adjustment, so there is less demand on the system itself. Generally it has gotten into the 50's during the day, and only down in the 30's at night. So I can't be sure that the adjustment is solely responsible for the amount of domestic hot water. I'm sure it is, but there is that factor to consider.

That being said, I am still planning on adding the indirect tank and zoning the house. The plumbing friend came over and we started looking at and scheming the new master bath and all the changes and additions we will be doing. I think those changes are being moved up to February as I just don't want to wait for the windows and siding to be done. I found out the windows will be at least 6 weeks to come in, so we will start the bathroom first.

I just lowered the hi from 190 to 180 (giving me the 20 degree difference in high and low) so I don't know that I will see any effect for at least a day.

I leave for the Borgata Casino tomorrow for about 2 weeks while I work (poker tournament series), so i won't be able to check on the house. but I'm sure wifey will be giving me updates!

Thanks for all the help fellas! I'll be sure to add follow ups as we move into rezoning the house and adding the tank!
 
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Old 01-20-10, 07:29 AM
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Thank you Trooper for that very good and very clear explanation of bypass. Now I can see I have the Boiler bypass you describe and now I think I actually understand what's going on!

thanks again!
 
  #35  
Old 01-20-10, 03:34 PM
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I just lowered the hi from 190 to 180 (giving me the 20 degree difference in high and low) so I don't know that I will see any effect for at least a day.
Not sure you will really see any effect from that, other than perhaps a teensy fuel saving... all that's going to do is shut the burners down 10 sooner on a heat call.

One thing I'm not sure is understood though... there doesn't have to be a 20 difference... that is the CLOSEST they should be, never closer. Now that you have increased the DIFF, you could in fact TRY lowering the LOW down to 150 and see what you get... after the coil is boiled out, and you have the Taco installed, you might even try dropping it to 140... each step cooler that you can go and still have adequate hot water is going to save you money on fuel.
 
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