Boiler

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Old 12-02-08, 07:02 AM
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Smile Boiler

My relief valve is leaking when I turn the thermostat up. I usually leave it at 71 degrees but when I turn it up to 72 or 73 the relief valve drips. Why is that? How can I fix it myself?

Also another question. I am going to install a Taco control valve control box. I already installed the valves. But on the two wires that come out of the factory installed transformer are the black and white power wires. They go to 120 VAC INPUT. Can I directly connect them to a circut breaker and can I also connect them to an existing power oulet? Thanks.
 
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Old 12-02-08, 07:31 AM
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What is your system's pressure when hot? Typcially, it will be less than 20 psi for a two-story house.

The relief valve is probably set for 30 psi. If it simmers when the system pressure is less than 20 psi, lift the manual lever, and see if you can clear out any debris on the seat.

Otherwise, replace the relief valve. You will probably have to drain the system to do that.

A 24-V transformer should be mounted on a steel electrical box (grounded), with the transformer primary (120-V) leads going into the box through a knock-out. Then, splice the leads to power with wire nuts inside the box. The incoming power to the box should be wired like any other receptacle, switch, or junction box - with wires in conduit or using Type NM wire (Romex).

Per code, you shouldn't try to rig up a plug and cord for the xfmr.
Doug
 
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Old 12-02-08, 07:35 AM
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Boiler

When it gets hot it is less then 20 psi. When I turn the heat up it goes over to about 30 psi. I already replaced the relief valve. What can I do to fix this problem?
 
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Old 12-02-08, 10:29 AM
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Originally Posted by mkdsk View Post
When it gets hot it is less then 20 psi. When I turn the heat up it goes over to about 30 psi. I already replaced the relief valve. What can I do to fix this problem?
If your expansion tank is conventional, it may be water-logged. If it is the bladder type, it may be low on air or leaking.
Doug
 
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Old 12-02-08, 12:10 PM
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Boiler

The relief valve was replaced a few weeks ago and the expansion tank was checked and the right amount of air was put in it. I was told to keep an eye on the boiler to make sure everything was okay. But when I turned the heat up just two degrees as I said the relief valve dripped a little. I was told that the expansion tank might be leaking but the expansion tank was just put on 2 years ago. Could it be leaking air already?????????? Can I replace the expansion tank myself? Is it easy? What is the cost of an expansion tank and do I just buy ANY kind of expansion tank? Thanks for all your help.

How do I tell if my expansion tank is conventional or bladder type?
 
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Old 12-02-08, 05:07 PM
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Describe the shape of the expansion tank - we will then be able to tell you the type. Does it have a Schrader (tire) valve on it? If yes, it's a bladder type.

If it's a newer bladder type, depressurize the system, and pump 10-15 psi into the tank with a bicycle pump.

Yes, the expansion tank could be leaking after 2 years, but not very likely.
Doug
 
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Old 12-02-08, 06:15 PM
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boiler

It does have a Schrader (tire) valve on it. But if I wanted to replace it can I do it myself? What else would be making the boiler PSI go up too high?
 
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Old 12-03-08, 01:34 PM
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The expansion vessel for the system could have breeched internally and has leaked its charge into the system. Or the valve is leaking make some soapy water up and splash it on the valve looking for bubbles to indicate a air leak.

Is the relief valve a pressure /temperature type . Is the system thermostat faulty and its heating to the temperature relief.
If the thermostat is faulty it would also raise the pressure in the system.

Check there is no sludge blocking the feed to the expansion vessel. Drain the system and remove the vessel check it isnt blocked.

Is the pressure relief valve on the primary heating circuit i.e the central heating side?
Maybe the filling point is passing and allowing a build up of pressure.

Some things I have mentioned may not be relevant as im in the UK and i belive your in the states but alot of systems are simplar in design. A photo would be a handy help if you need further assistance
 
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Old 12-03-08, 03:32 PM
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I am having similar issues with high pressure…See my post yesterday "high Boiler Pressure". I have tried it all with no success. I may just replace the extol bladder tank anyway as not convinced that it is OK. I am having similar issues with no suggestions. You should be able to do it your self. Go to the Amtrol web site for install instuctiuons for Extrol tanks.
 
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Old 12-03-08, 06:06 PM
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Boiler

I am just going to replace the expansion tank. It is still under warranty so what could it hurt. ANYONE ELSE KNOW WHAT COULD BE MAKING THE BRAND NEW RELIEF VALVE still drip when I turn up my thermostat other then the expansion tank?
 
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Old 12-04-08, 07:28 AM
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You may want to check the pressure reducing valve/fill valve. This valve is connected to the city water line and provides makeup water for boiler. The valve may be leaking through and overpressuring the heating system.

With system cold, close the shutoff valve to the pressure reducing valve and relieve the boiler pressure to @12 to 15 psi. Leave this valve shut and fire boiler and monitor the pressure. If pressure moves a couple psi up at the boiler high limit then the pressure reducing valve might need adjustment, cleaning or replacement. If the pressure goes high and triggers the pressure relief valve, then the problem is something else.

Try this and let us know how it turns out.

Originally Posted by mkdsk View Post
I am just going to replace the expansion tank. It is still under warranty so what could it hurt. ANYONE ELSE KNOW WHAT COULD BE MAKING THE BRAND NEW RELIEF VALVE still drip when I turn up my thermostat other then the expansion tank?
 
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Old 12-04-08, 08:48 AM
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Boiler

You said with system cold, close the shutoff valve to the pressure reducing valve and relieve the boiler pressure to @12 to 15 psi. How do I reduce the pressure to 12-15 psi? Do I drain some water out?
 
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Old 12-04-08, 09:19 AM
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Yes, slowly drain some water out.

Originally Posted by mkdsk View Post
You said with system cold, close the shutoff valve to the pressure reducing valve and relieve the boiler pressure to @12 to 15 psi. How do I reduce the pressure to 12-15 psi? Do I drain some water out?
 
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Old 12-04-08, 09:56 AM
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Boiler

Another question for you. I checked the air pressure in the expansion tank and it it at 15. Shouldn't it only be at 12? Also, my expansion tank is connected to a red device and on it it says "Taco Air Supply" I am not sure what that is..
 
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