Stumped with hydronic system
#1
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Stumped with hydronic system
Two zone system with one zone not working (upstairs). I replaced an analog thermostat thinking it was the problem, no change. I replaced the motor on a Honeywell v8043e1012 zone valve. After turning on the electricity and increasing the thermostat above current temp, the valve opens, furnace kicks on then it stops after a minute. The valve remains open (assuming because the valve trigger moves freely).
Thinking it was the end switches, I replaced the power head, Honeywell 40003916-026. After turning on the electricity, the valve opens, furnace kicks on then stops again after a minute.
My knowledge on this stuff is minimal at best and I've learned more about furnaces from reading these forums. Any suggestions (aside from calling a professional) will be appreciated.
Thinking it was the end switches, I replaced the power head, Honeywell 40003916-026. After turning on the electricity, the valve opens, furnace kicks on then stops again after a minute.
My knowledge on this stuff is minimal at best and I've learned more about furnaces from reading these forums. Any suggestions (aside from calling a professional) will be appreciated.
#3
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Stupid question:
When I replaced the analog thermostat, there was a red and green wire. According to the wiring for the analog, the green wire was attached to where a white wire should be. Assuming the green was a white wire, I attached it to the W terminal on the new thermostat. Could this be the issue all along? If I attach the green wire to the G terminal, how will this affect the system if it is wrong?
When I replaced the analog thermostat, there was a red and green wire. According to the wiring for the analog, the green wire was attached to where a white wire should be. Assuming the green was a white wire, I attached it to the W terminal on the new thermostat. Could this be the issue all along? If I attach the green wire to the G terminal, how will this affect the system if it is wrong?
#6
Boiler is at 200F, according to the thermometer on the furnace. The thermometer also has a pressure gauge. Is this the right thermometer?
200f is a bit high. What type of aquastat do you have? You may want to turn the temp down to 180F...
What type of hot water heater do you have?
#15
You have a tankless coil there.. set the HI in aquastat to 180F.. You said is was... and the low to say 150F.. Set the differential to 10..
OK so the zone with no heat you said the zone valve is open and activated by the t stat? ( You checked the lever and it moves freely?
OK so the zone with no heat you said the zone valve is open and activated by the t stat? ( You checked the lever and it moves freely?
#16
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Yes, the thermostat activates the zone valve. The lever moves freely. The pipe above the zone valve in question is cold. Also the pipe leaving the boiler to the expansion tank is very warm and the pipe above the expansion tank is warm to the touch. When the pipes split to go upstairs to both zones, both are warm.
Could there be air that needs to be bled to allow proper circulation of the warmed water?
Could there be air that needs to be bled to allow proper circulation of the warmed water?
#17
In your first pic there is an air vent left of the flue on top of the boiler.. Loosen that top screw.. air may come out.. Leave it loose.. If water comes out tigthen the cap. That will need to be replaced then..
[ATTACH=CONFIG]64906[/ATTACH]
Tell me what the pressure gauge says on the boiler..
[ATTACH=CONFIG]64906[/ATTACH]
Tell me what the pressure gauge says on the boiler..
#18
I have to run out, but if you need to add water to the boiler you lift that brass handle on the fill valve. Thats the device on the left in pic where the white wire lays on it .. Follow white wire from right to left and youll see fill valve..
The boiler should have about 15 psi in it when boiler is coolish..
[ATTACH=CONFIG]64908[/ATTACH]
If you need to bleed that zone then turn off both t stats so zones are closed.. Hook up hose to boiler drain on zone in question.. Drain some water in 5 gallon bucket.. You may need to raise the pressure in the boiler when doing this. Thats the fill valve I discussed above...
Dont let the pressure go over 30 psi when doing this..
Then close fill valve and stop draining water from boiler drain.. Make sure pressure is around 15 psi.. Then run boiler again and let us know...
[ATTACH=CONFIG]64909[/ATTACH]
The boiler should have about 15 psi in it when boiler is coolish..
[ATTACH=CONFIG]64908[/ATTACH]
If you need to bleed that zone then turn off both t stats so zones are closed.. Hook up hose to boiler drain on zone in question.. Drain some water in 5 gallon bucket.. You may need to raise the pressure in the boiler when doing this. Thats the fill valve I discussed above...
Dont let the pressure go over 30 psi when doing this..
Then close fill valve and stop draining water from boiler drain.. Make sure pressure is around 15 psi.. Then run boiler again and let us know...
[ATTACH=CONFIG]64909[/ATTACH]
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Sorry had to run an errand too. The current psi is at 15. I opened that air vent (it's the one that looks like a cup with a lid?) and water leaked out. When you say it needs to be replaced, is it broken? If it is shouldn't it affect both zones?
#24
Sorry had to run an errand too. The current psi is at 15. I opened that air vent (it's the one that looks like a cup with a lid?) and water leaked out. When you say it needs to be replaced, is it broken? If it is shouldn't it affect both zones?
Yes that device needs to be replaced. It eliminates the air in the system...
What is the proper psi while the boiler is on? It was at 15 psi when I drained it cold. Now that the boiler has been on, the psi is slightly over 30.
A cold boiler it should be 12-15psi..
Turn the boiler off.. Drain some water out till the gauge reads 10 psi and wait a minute.. It should fill itself to about 12-15 psi.. If it goes higher then the fill valve is not functioning and would need to be replaced..
To get you by when you do the test above simply turn off the water feed when the psi gets up to 12-15 psi.. That valve should be right before the fill valve somewhere.. I think I see a blue handled valve just before it...
The fill valve may be able to be adjusted and not replaced.. Look for instructions online.. ( Ill try to find something later)
Also high PSI can be cause by a faulty exp tank... The psi in the tank needs to be tested.. If you let some air out of the exp tank and water comes out its shot.. The exp tank needs to be tested with the boiler at 0 psi...
Read here....
http://www.doityourself.com/forum/bo...sion-tank.html
Let me know....
#26
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Will a busted expansion tank introduce enough air into the system to prevent proper hot water circulation? I'm trying to prevent this problem (at least slow it down) from happening.
If I can get the psi to 12 when cold, how much should it go up when hot?
P.S. Thank you for taking the time to answer these questions, it is truly appreciated.
If I can get the psi to 12 when cold, how much should it go up when hot?
P.S. Thank you for taking the time to answer these questions, it is truly appreciated.
#27
I dont see an exp tank on your system.. Can you find it and take a pic?
Exp tank is for thermal expansion... Not for air.. ( But depends on what exp tank you have)
Hot the boiler should ride around 20 psi or so...
Exp tank is for thermal expansion... Not for air.. ( But depends on what exp tank you have)
Hot the boiler should ride around 20 psi or so...
#28
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The expansion tank is situated near where the pipe from the boiler splits into the two zones.
I did what you suggested with lowering the pressure. At 15 psi, I stopped the draining and the valve did not increase the psi. I just turned on the downstairs tstat and after 10 minutes the psi is up to 25.
#29
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Looks like it will be a cold night tonight. The pressure is back up to 30psi and that's just turning on 1 zone. I will turn off both thermostats and drain the pressure back to 15 psi for the night.
If the fill valve is functioning, where else can the water come from?
How can I test to see if it is my gauge that is wrong?
Once the pressure is down to 15psi, is the next step to close the fill valve and run the system?
If the fill valve is functioning, where else can the water come from?
How can I test to see if it is my gauge that is wrong?
Once the pressure is down to 15psi, is the next step to close the fill valve and run the system?
#30
Once the pressure is down to 15psi, is the next step to close the fill valve and run the system?
Tap the exp tank.. does it feel heavy and full if water?
Did you let air out to see ifs water logged?
How to check pressure gauge link below...'
http://www.doityourself.com/forum/bo...ure-gauge.html
Last edited by lawrosa; 04-10-16 at 07:47 AM.
#31
If tank seems good and you dont want to drain system down just add some air to it..... Its better then no air...
Add 12 psi...
Add 12 psi...
Last edited by lawrosa; 04-10-16 at 07:48 AM.
#32
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Hello again. I have not tested the exp tank yet but I will before replacing it. Could you walk me through an exp tank replacement? As in what's an easy step by step approach. I know that I have to relieve the pressure to near zero. I have spigots right above the two zone valves and another spigot at the bottom of the boiler on the right. I have a shut off valve before the fill valve. It's a tight space to get the tank off and I want to minimize the amount of water that will be released when I take off the tank.
#34
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Update. Checked the exp tank (correctly), pressure was low. I pumped it correctly (using the instructions from your link). The exp tank is mounted sideways and that might play a role, I'm not sure.
When I opened the fill valve, it went above 15 psi. I closed the fill valve and drained some water until 10 psi. Opened the valve again and it went passed 15 psi. I was thinking it's the fill valve.
Now it gets interesting. I closed the fill valve again and let it drain until 10psi. Closed the drain and the psi continued to drop until 5psi. I re-checked the exp tank pressure and it was steady at 12.
I finally stabilized the psi of the boiler at 12 psi with the fill valve closed. I turned on the boiler and the psi is now at 35psi. I am currently relieving the pressure.
So, it's not the thermostat (new and checked wiring), it's not the zone valve (new motor, new power head, re-checked wiring), it's not the exp tank, it's not the fill valve. What's left??? Could be an issue with the heating coil for hot water storage tank. Or is it truly time to call a pro? Should I just change the exp tank in the case that the sideways mounting is giving me a false positive reading??
When I opened the fill valve, it went above 15 psi. I closed the fill valve and drained some water until 10 psi. Opened the valve again and it went passed 15 psi. I was thinking it's the fill valve.
Now it gets interesting. I closed the fill valve again and let it drain until 10psi. Closed the drain and the psi continued to drop until 5psi. I re-checked the exp tank pressure and it was steady at 12.
I finally stabilized the psi of the boiler at 12 psi with the fill valve closed. I turned on the boiler and the psi is now at 35psi. I am currently relieving the pressure.
So, it's not the thermostat (new and checked wiring), it's not the zone valve (new motor, new power head, re-checked wiring), it's not the exp tank, it's not the fill valve. What's left??? Could be an issue with the heating coil for hot water storage tank. Or is it truly time to call a pro? Should I just change the exp tank in the case that the sideways mounting is giving me a false positive reading??
#35
Could be an issue with the heating coil for hot water storage tank.
Get the boiler psi to 15 and shut off the fill valve.. Leave the fill valve off once psi set..
Then when you run the boiler with the fill valve closed you say the psi rises to 30 + psi??
Try it again if so but close the blue handle to the tankless coil here after you set the boiler to 15 psi then open that drain valve with the blue handle below it.. ( Use bucket under it.) Drain the water.. It should be a small amount. What your doing is shutting the cold water feed to the tankless coil..
Do not use any water in the house when doing this test..
Run the boiler. Tell us what happens.. ( Either the boiler will run normal or pressure will be lost in the boiler).
[ATTACH=CONFIG]65003[/ATTACH]
#36
When I opened the fill valve, it went above 15 psi. I closed the fill valve and drained some water until 10 psi. Opened the valve again and it went passed 15 psi. I was thinking it's the fill valve.
You should be able to adjust the fill valve to work properly, maybe not..
Read here.. ( 3. To reset the regulator valve

http://media.wattswater.com/1910265.pdf
#37
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Wife gave me the evil eye and asked me to call an HVAC technician. They confirmed that the heating coil is leaking. They saw that the pressure was rising with the fill valve off, when they cut off water connecting to the water tank, the pressure didn't budge. They also showed me that the pressure decreased when they drained water from the storage tank.
Last two questions, they recommended to replace the whole boiler. They also said that if they can get the coil, they can also replace that. Last option they gave me was to revamp the system and go with propane. If you were in this predicament, would you a) replace coil, b) replace with an oil boiler, c) replace with a gas boiler?
Thank you again for your time and help.
Last two questions, they recommended to replace the whole boiler. They also said that if they can get the coil, they can also replace that. Last option they gave me was to revamp the system and go with propane. If you were in this predicament, would you a) replace coil, b) replace with an oil boiler, c) replace with a gas boiler?
Thank you again for your time and help.
#38
If you were in this predicament, would you a) replace coil, b) replace with an oil boiler, c) replace with a gas boiler?
Why replace the boiler? There is nothing wrong with it... Unless the boiler itself is leaking its probably just a waste of money...
Replace the coil yes.. Thats what I would do... But.....
I would probably remove the coile and add a dummy plate to do away with it .. I would then install an electric water heater..
This would require running a 240v circuit from the panel to the water heaters location...
What are your electric rates? ( Im comparing electric to oil prices...)
Youll have better comfort and save on oil.. You could probably make your boiler cold start then and save even more oil..
If you do replace the boiler down the road stay oil and add an indirect heater maybe..
They also said that if they can get the coil, they can also replace that.
#39
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According to the HVAC tech, the water storage tank I have now already is an electric water heater. The boiler was providing hot water to it from the coil and the electricity keeps it warm. They can pipe just cold water to it and it will heat the water for us.
They also don't recommend just capping the coil or putting a dummy plate because it could be a heat seeking missle if the pressure gets too high. But then they would be glad to do it for us... I'm skeptical. Is there any truth to this statement? How long can the boiler last with a dummy plate instead of the coil? Is this a temporary fix or can we rely on this until we can afford a buderus boiler?
Thanks again
They also don't recommend just capping the coil or putting a dummy plate because it could be a heat seeking missle if the pressure gets too high. But then they would be glad to do it for us... I'm skeptical. Is there any truth to this statement? How long can the boiler last with a dummy plate instead of the coil? Is this a temporary fix or can we rely on this until we can afford a buderus boiler?
Thanks again
#40
They also don't recommend just capping the coil or putting a dummy plate because it could be a heat seeking missle if the pressure gets too high. But then they would be glad to do it for us... I'm skeptical. Is there any truth to this statement? How long can the boiler last with a dummy plate instead of the coil? Is this a temporary fix or can we rely on this until we can afford a buderus boiler?
No risk of explosion... They just trying to scare you...
Get a second and third opinion...
Why do you want a Buderus boiler?
Whats your location? Its not in your profile