Baseboard not getting hot

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  #41  
Old 11-17-12, 10:21 AM
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I would open the boiler drain my self. But if you opened the relief valve before and it did not leak, go for it.

I am going out for a few hours. Be back later. Good luck and let us know.

Oh what are the aquastat settings?
 
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  #42  
Old 11-17-12, 01:03 PM
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well i followed all the directions and aafter firing the boiler, i stil have the same problem...some baseboards are hot and some are stone cold. Thanks every one for all the help....
 
  #43  
Old 11-17-12, 01:11 PM
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The base boards that are stone cold i would suggest bleeding them until you start getting hot water out of them. May take some time. That may get things moving.

Hey is it only one side of the Y getting hot and the baseboard on the other side is cold? Or does it vary?

Take wide angles of the pipes above. If there are valves to isolate both pipes after the T you possibly would have been done.

Its just you fail to provide up with proper pics. I am not there so cannot see what you have to work with. We may see things you dont...
 
  #44  
Old 11-30-12, 02:29 PM
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I am back with a couple questions. 1- Why i can't get the circ pump running even when i turn the low limit on the aquastat to 110F? I checked the 2 terminals and there is no power. 2- Water is dripping from the air vent on top of the expansion tank. Do i need to replace it?
 
  #45  
Old 11-30-12, 03:14 PM
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The lo limit hold off the circ until the set point is reached basically.. What are you trying to do?

Yes air vent needs replacement....... [NJT edit - close the cap for the time being]
 

Last edited by NJT; 11-30-12 at 04:15 PM.
  #46  
Old 11-30-12, 04:02 PM
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an old problem that started after i let somebody work on my boiler (replaced so far expansion tank, backflow preventer and relief valve). There is air in the system and we can't get rid of it. The guy now is telling me that the pump is too small. I consulted with another plumber and he is telling me that the pump size is fine. The problem is in 1 baseboard that is stone cold when the pipe leading to it is hot as hell.

When i try to bleed that 1 cold baseboard, air,cold water and then warm water will come out. But i can never get the whole baseboard to get hot. I observed today that the pump doesn't come on when it suppose to. With the boiler running,there is no power leading to the pump. The aquastat setup is like this: 170 LO / 190 HI and 10 differential. I hope i do not have to change the aquastat now....
 
  #47  
Old 11-30-12, 04:12 PM
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The guy now is telling me that the pump is too small. I consulted with another plumber and he is telling me that the pump size is fine.
Your first plumber is looking for more money from you. The second has a conscience.

The aquastat setup is like this: 170 LO / 190 HI and 10 differential. I hope i do not have to change the aquastat now....
You might... but first,

TURN THE LOW BACK DOWN TO 140 ! with a 20 differential!

TURN THE HIGH DOWN TO 180

and LEAVE THE SETTINGS ALONE!

If you have not yet verified that your pressure gauge is accurate, then we can not continue any further.
 
  #48  
Old 11-30-12, 04:18 PM
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the pressure gauge is fine...i just replaced the old one for the sake for it. I even installed a second one on the boiler drain as a backup check.And both are giving me the same pressure reading.
 
  #49  
Old 11-30-12, 04:27 PM
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sorry i forgot to mention one more thing. I have a tankless coil in my boiler for hot shower/laundry etc... Will 140 high enough to provide hot water in the showers?
 
  #50  
Old 11-30-12, 05:25 PM
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And both are giving me the same pressure reading.
And what pray tell IS that pressure reading when the boiler is COLD ?

What is the pressure reading when the boiler is HOT ?

I have a tankless coil in my boiler for hot shower/laundry etc... Will 140 high enough to provide hot water in the showers?
It should... but depending on how much calcium and magnesium ( aka 'lime' ) has built up inside, it might not be very efficient...

Even if it were BRAND NEW, that tankless boiler coil is absolutely without a doubt the WORST way to create hot domestic water for home use. The only thing worse is a kettle on a wood stove.

Thing is, if you set it to 170 where you had it, you run the risk of COOKING YOURSELF OR YOUR FAMILY MEMBERS ALIVE. The potential for 170 water delivered to your taps is REAL! Think about how quickly one would suffer third degree burns when in contact with that water... about 1 or 2 seconds...

Even 140 is too hot for tap water.

Not to mention the amount of FUEL you will have to burn in order to maintain the boiler at that temperature... crazy ridiculous waste of fuel... it would still be a terrible waste to maintain it at 140, but not NEARLY as bad as 170!

TELL US though, do you know if there is a TEMPERING VALVE on the domestic hot water outlet that will LIMIT the temperature of the water delivered to the taps to a SAFE temperature of 120-125 F ?

Are you planning on living in this home for a while?

STRONGLY consider getting a REAL water heater and convert your boiler to COLD START and ABANDON that "thankless coil" water heater in your boiler.
 
  #51  
Old 12-01-12, 06:52 AM
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The pressure reading is at 12 when cold and around 20 when hot. I have been living in the house for the last 10 years and count on staying here for another 10. The boiler manual calls for a setting of 190/210/25.But the last technician who worked on the boiler set it at 170/190/10. I am going to follow your advice and set it at 140/180/20. However,my problem is not with the setup but the fact that i can't bleed the system. I have 1 baseboard that refuses to get hot no matter how long i bleed it.

Yes there is a tempering valve on the domestic hot water outlet.

I have been thinking about changing to a normal water heater.But the quotes i am getting are in the $2200 range (a lot of money i think).
 
  #52  
Old 12-01-12, 09:38 AM
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The boiler manual calls for a setting of 190/210/25.
I would have to see that to believe it. What make/model is the boiler again?

However,my problem is not with the setup but the fact that i can't bleed the system. I have 1 baseboard that refuses to get hot no matter how long i bleed it.
Right, we realize that, but the safety of you and your family is primary.

Yes there is a tempering valve on the domestic hot water outlet.
That's good... at least you won't be calling 911 anytime soon.

With a monoflo, you probably need to bleed the system with the circulator pump running. Were you able to determine why it is that you thought the pump was not running?

quotes i am getting are in the $2200 range (a lot of money i think).
What type of water heater is the quote for? A stand alone unit? An INDIRECT?

Yes, 2200 sounds a bit high, but depending on the scope of work... might be reasonable.

If you DO switch over, please make sure that the work INCLUDES converting your system to COLD START by swapping out the aquastat for an appropriate model.
 
  #53  
Old 12-01-12, 10:19 AM
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Are there any shutoff valves on the baseboard returns? On my monoflow system, two of the baseboard branches have shutoff valves located on the return branch piping in the basement. When I bleed those baseboards, after doing it with the valves open, I then have to shut the valves in order to ensure that I'm purging the supply side piping of any air.

It took me a while to figure out why those valves were there...I originally thought their purpose was to regulate flow through that branch, but after draining the system a few times, I found out that those two branches were (are) the the most difficult to purge.
 
  #54  
Old 12-01-12, 10:54 AM
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Here are a couple graphics that may help explain why monoflo systems can be so difficult to bleed:

This shows the basic setup of a monoflo radiator piped off the main line. Note that when you open a bleeder at either end of the radiator, the water pressure can come from EITHER end. If the radiator happens to be pitched such that there is no air bubble UNDER THE BLEEDER, that air may be VERY difficult to get moving toward the bleeder location.



This graphic shows the effect of an air bubble blocking flow. Imagine if this air bubble exists at the end OPPOSITE the bleeder. In a monoflo system, how does one get that bubble to move to the other end?



Rock described valves on his system... the reason for those valves was to place a 'roadblock' to the water coming from the 'wrong' end of the radiator and when closed would force the water to flow in the desired direction so as to move the air out the bleeder.

Remember, water will ALWAYS flow from high pressure to low pressure, and will always take the path of least resistance to that flow.
 
  #55  
Old 12-01-12, 11:55 AM
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Great explanation....you nailed it Troop.
 
  #56  
Old 12-01-12, 02:11 PM
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Great info Troop. So far i have learned that my bleeders are in the right location. For some time now i have been thinking about installing those valves that Rock mentioned.

I think my system is not well designed. Anyway, in the manual for my Burnham V7 series oil fired boiler (page 19) i read: On water boiler with tankless heaters, set operating control dial on L8124 AT 190/210/25 control must be a minimum of 20 below high limit setting. Set differential at 25.
 
  #57  
Old 12-01-12, 02:32 PM
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(page 19) i read: On water boiler with tankless heaters, set operating control dial on L8124 AT 190/210/25
Good Lawd, that's just crazy stuff they wrote! There is no reason to run the temp that high, none at all.

You haven't told us if you've got the problem with the pump figured out yet?
 
  #58  
Old 12-01-12, 02:47 PM
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i figured the pump is on/off depending on the water temperature in the boiler. But, i would like to bleed the system cold with the pump running. And,I still can't figure out how to do that. I thought by putting the low setting limit to a bare minimum the pump should automatically come on, but it is not happening. I really do not know what else to do.
 
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Old 12-01-12, 02:53 PM
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No... with the aquastat that you have on the boiler you may not be able to run the pump without the burner in order to bleed...

It's probably better if the boiler is as hot as you can get it though, you might have better luck bleeding HOT HOT than if cold.

So try it... turn the thermosat all the way up and just let it run and get hot hot hot and being careful not to burn yourself go ahead and bleed that rad with the pump running.
 
  #60  
Old 12-01-12, 02:58 PM
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all right i am going to give it one more try in the morning....I will let you know how it goes. Thanks for all the help....
 
  #61  
Old 12-01-12, 03:02 PM
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OK, good... I just looked up your nickname meaning... I bet you are NOT! LOL!
 
  #62  
Old 12-01-12, 03:13 PM
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of course not lol...now you mentioned it,i don't even know why i picked this nick.
 
  #63  
Old 12-01-12, 09:15 PM
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ha ha ha ... hey, that make two of us ( me and mine )!
 
  #64  
Old 12-02-12, 10:30 AM
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Troop i have been bleeding all morning with no results. Air and then hot water and then more air is coming out of the bleeder. No way there could be so much air in the system. It looks like i am introducing the air from somewhere in the sysstem. Could that be possible?

The 1 1/2" pipe coming from the boiler is very hot. Out from that pipe there is a T with a 3/4" pipe leading to the baseboard. That pipe is also hot. The water coming out of the bleeder is also hot. Why then the baseboard refuses to get hot? Could it be that i need to bleed from the outlet of the baseboard? And if it is so. How do i do that
 
  #65  
Old 12-02-12, 11:05 AM
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Air and then hot water and then more air is coming out of the bleeder.
If you are getting air, you are making progress!

Turn the system off and let sit for an hour or so, then before you turn back on, open the bleeder again. Hopefully some air will float and collect underneath the bleeder. After this, turn the system back on again and bleed some more.

Even though the other radiators are now making heat, don't neglect to bleed them a little bit more also. It's possible that there is some air in those still and the fact that they are heating it is possible that the flow from those is picking up small amounts of air and it is collecting in the trouble radiator.

I know it's frustrating, but that's why they designed monoflo systems... they were sadistic and just wanted to mess with us in the future!

No way there could be so much air in the system. It looks like i am introducing the air from somewhere in the system. Could that be possible?
I suppose it's possible, but not likely. It seems like a lot of air, but it's really a lot less than you think!

Could it be that i need to bleed from the outlet of the baseboard? And if it is so. How do i do that
Which end of the baseboard is the bleeder installed? At the inlet side? That may cause your trouble... the bleeders should always be installed downstream side.

Mantente fuerte! Usted va a ganar!
 
  #66  
Old 12-02-12, 11:22 AM
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I went downstairs and look at the pipes, the bleeders are definitely at the inlet side. I
 
  #67  
Old 12-02-12, 11:29 AM
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So try alternating between bleeding hot with the pump on and letting system rest and bleeding cold with pump off.

Make sure you keep pressure high in system while bleeding.
 
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Old 12-02-12, 11:46 AM
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I see that you are keeping up with your spanish... i Like that lol lol. One more thing..i can't figure out how the cover of the baseboards are mounted (see attached pic)



 
  #69  
Old 12-02-12, 02:29 PM
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S, Google Translate es bueno para algo!

can't figure out how the cover of the baseboards are mounted
I've never seen that type myself so I can't help other than to say that they all pretty much 'clip' on somehow.

Try taking a small mirror and looking up from the bottom, maybe you will get some clues how they come off?
 
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