Tarm - 0 pressure reading

[JayDogg]

My tarm gauge on the front of the unit is saying the pressure in the system is 0. Doesnt make sense to me, the gauges I have on the supply line coming out the boiler says around 20 and the gauge on the back of the OB says around 20. Anyone ever have this happen? Is there some sort of reset button or something?

 

[webie]

I would guess chances are the gauge is not accurate . I have seen mine down to about 4 when my system was cold and the one on the gas says 12 . I doubt someone shut your supply and return valves off to the tarm ? I am not sure on your 40 but On my 60 there is a air bleeder under the top cover you could just crack that for a second just to verify there is pressure .
Also I do not know what you have for an expansion tank but check it to make sure it didnt water log . I ended up draining mine because when the system cooled down finally after a long winter of heating some how I lost my air cushion in my expansion tank and the pressure went down and the system eventually called for more make up water only to have me blowing my pressure relief valve the next time I heated it up .

 

[JayDogg]

Can I just turn the valve on the bottom of the expansion tank and see if any water comes out? I have been letting the fire go out every day now since its been getting warm outside so maybe the tank filled with water like yours did.

 

[webie]

Not sure what you have for a expansion tank . I doubt you can just turn that valve it will start to bleed water or air but will only be replaced by more water as your systems pressure drops . The only way you can bleed off a water logged pressure tank is to isolate it which I doubt you can or shut the system supply off and let the tank drain to zero and system zero then close the tank valve and turn back on the supply . Can you post a pic of your expansion tank ?

 

[webie]

Rule out the easy stuff first , lets just say its a faulty gauge .
Are you cold and 20lbs of pressure ?

 

[RobC]

The top of the tank where it's connected to the boiler lines has water in it. Go down about 1/3 the way on the tank and you'll see an indent that goes around the tank. That's where the rubber bladder is the rest of the tank contains air. From the factory they are charged at 10 - 12 psi ( I think those are the numbers ). Any way you do not want to press the schrader valve on the bottom of your tank or you will let out air pressure out of the tanks then the tanks will have to be reset. If you tap on the lower part of the tank they should sound hollow.
Rob