Boiler doesn't push water to baseboards


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Old 10-17-18, 07:17 AM
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Boiler doesn't push water to baseboards

Hi,

I have a water boiler that receives the thermostat call and the boiler turns on the flames and hot water is pushed by the Taco circulator pump but it only goes up 3-4 feet into the pipe and the remaining pipe is cold or room temperature. I replaced the Taco circulator pump to another boiler that I have and it worked fine there.

I did just found out that the expansion tank has a little leak and I'm wondering if that would impact it? it leaks about 1-2 table spoons of water, not constantly but perhaps every hour or so. I just saw the leakage this morning.
The Circulator pump gets very hot and stays hot irrgardless of the boiler turning on the flames. The temperatures also stays at about 160 degrees..

Any suggestions?

thanks,
acm66
 
  #2  
Old 10-17-18, 07:57 AM
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The problem isn't the pump. What is the system's pressure? The system is probably air bound. When fresh water is brought in to replace any leak, it brings in entrained and dissolved air. Inspect your entire system for any other leaks, replace the expansion tank, fix any other leaks, and purge the system of air. Verify that you have a working air-removal device and that the Schraeder valve's cap isn't screwed down tight.
 
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Old 10-17-18, 08:24 AM
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The pressure is about 15 which is normal.
 
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Old 10-17-18, 11:08 AM
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You need to vent the air from the system and also check the pressure gauge to make sure it is working. From your explanation of the system, it seems to be full of air and does not have hardly any pressure in it.
 
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Old 10-19-18, 12:20 AM
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I never did bleed the water boiler(new owner) so I have a few questions.
1. I know where the drainage valve is and I will connect a hose to it to the exterior of the house.
2. I turned the electrical red switch to off.
3. The water source valve has been turned off.
4..the fill valve is currently set with the metal tab points to the same direction of the output (right side) I presume this means itís open?
5 should I open the air vent during the bleed or keep it closed?

Thanks for your help.
acm66
 
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Old 10-19-18, 03:12 AM
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You need to go to the highest point in the system and look for a bleed/vent valve and open it slowly. Leave it open until water runs from the vent valve. If the air stops blowing out of the vent and no water has vented, the water pressure in the system needs to be a little higher. ( for each pound of water pressure the water in the system will rise about 2.3 feet or .43 pounds = 1 foot of elevation of the water). So, if the height from the pressure gauge to the top of the highest radiator (your vent) is 20 feet then 20 feet X .43 = 8.6 pounds pressure and add a couple pounds pressure for a safety margin.Do the venting with the boiler and pump off. Vent from as many vent valves as you can find. Then run the boiler and pump for a few minutes, then shut off the boiler and pump and vent again. you may need to do this a number of times to expel all the air. If you still do not get heat in the whole system, re-post and we will try to figure out what the problem is.
 
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Old 10-20-18, 05:32 PM
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I bleed the water. Boiler about 7 times over two days. Some air came out along with dirty water. The last bleed there was no signs of air and the water is clean.

I started the boiler and the flames started but the hot water still did not make it to the second floor. However the nearby pipes of the boiler were very hot. I also changed the taco circular pump from another boiler where it was working well. The only symptom that I heard was water slushing around inside the boiler. After the flames turned off.

Any clues what it could be?

thanks
acm
 
  #8  
Old 10-20-18, 05:38 PM
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Try temporarily jacking up the system pressure to 25 psi, and purge again. Leave the valve from the water inlet open while purging. If you still can't figure it out, probably best to call in a recommended technician.
 
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Old 10-21-18, 03:14 AM
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Originally Posted by acm66
". . . I also changed the taco circular pump from another boiler where it was working well. The only symptom that I heard was water slushing around inside the boiler . . ."
Make sure the replacement pump is installed with its housing in the correct direction.

These Taco pumps are directional, and the pump must match the flow designed for your system so that it's not pushing water against any back flow preventer or Flow Check Valve you may have.

The Pump's Directional Arrow is embossed right in the boilerplate of the Housing, and before doing anything, you can look to make sure the replacement Pump is set up exactly the same as the Pump that you removed from your system (if you can remember). Installed in the opposite direction, it runs but you get very little movement and maybe even the thrashing that you hear . . . . and may damage the Pump's Impeller and Bearings.

When I did this to myself recently, I wrote about it in this related thread, which may be helpful:

Importance of knowing the "direction" of your flow
 

Last edited by Vermont; 10-21-18 at 03:41 AM. Reason: Added Link
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Old 10-21-18, 05:48 AM
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I checked the direction of the taco pump. It points down as the other two taco pumps in the other identical boiler.

How do I increase the pressure to 25 from 15?

thanks for your suggestions

acm
 
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Old 10-21-18, 06:48 AM
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Find your automatic fill valve (a.k.a. pressure reducing valve) in the city water supply to the boiler. There should be a fast-fill lever on top. Lift the lever while watching you boiler pressure gauge. If you are unsure, please post some pictures of your system.
 
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Old 10-21-18, 08:23 AM
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I was able to increase the pressure to 35 and I bleed it with the water source on for about 5 minutes.No air or dirty water then I dropped the pressure to 15 or so. I turned on the boiler flames came on but the heat never made it to the baseboard on second floor.


Any other ideas?
 
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Old 10-21-18, 08:35 AM
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Originally Posted by acm66
". . . It points down as the other two taco pumps in the other identical boiler . . ."
But is that the way the original Pump was pointing in THIS System ?

The Boilers may be identical; but the heating systems may be configured differently.
 
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Old 10-21-18, 08:55 AM
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When you said that you changed the taco pump from 1 boiler to the other, did you change the whole pump (take it off at the piping flanges) or just the motor. I ask this because if the piping near the boiler is all that is getting hot I would guess that the pump is not pumping water. Can you post a picture of the pump and boiler?
 
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Old 10-21-18, 11:36 AM
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a,
Is it possible to post pics of the system. That would be very helpful.

One other thing that you mentioned about getting the system up to 35 PSI to bleed it.

At 35 PSI the relief valve would have gone off and since you didn't mention it my guess is you either have a defective pressure gauge or your relief valve is frozen shut.

In either case something needs attention. If your pressure gauge was reading 35 with no release at 30 from the PRV and it's working that means your gauge is off and if that's the case what is the true boiler pressure when your gauge reads 15 PSI.

If your gauge is off by at least 5 lbs or so you are running such low pressure that your feed valve is feeding fresh water in along with more air.

Not saying that is your problem but it could bear looking into.

Going in another direction, where the hot water pipe seems to cool is there any type of control there like a FLOCHECK valve that may be sticking. or anything that you can open to get manual flow to the system.

Just a thought. Hope this helps a little.
 
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Old 10-22-18, 08:17 AM
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I just had a heatingl guy look at my boiler. He said the pump wasnít working and it also needed a relay switch.

Is it easy to setup a relay switch to the boiler and connected to the new pump? Are there instructions to do that?

 
  #17  
Old 10-22-18, 10:38 AM
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You posted that you verified the pump was working. What changed that the guy found the pump not working and what purpose is the relay for.
 
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Old 10-22-18, 01:46 PM
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May I ask how much the "heating guy" charged for this service call/diagnosis ?

And how much would it have been if he actually implemented his solution ?
 
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Old 10-22-18, 03:08 PM
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Two floors usually means there is at least 2 zones of heat distribution and each must be bled separately even though there is just 1 circulating pump. Is there a separate t'stat and zone valve for each floor?
 
  #20  
Old 10-23-18, 02:14 PM
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Did you bleed the system at the second floor radiator(s)? On at least one radiator per floor there should be a small valve sticking off the pipe elbow that you can open with a small screw driver to let the air out of that radiator. Sometimes there might be a couple bleeders throughout the system and you should make sure that none of them have air.

That leak in the expansion tank could be causing some of this problem too, when the filler lets in new water to replace what leaked out, air gets in as it is dissolved in the water. Further if this is a membrane tank and your expansion tank has completely failed and is leaking out of the schrader valve the system will not pressurize properly and could become dangerous to operate. The expansion tank needs to be more closely evaluated to fix that leak and possibly repair, replace or recharge.
 
 

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