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Last post
GFrazier
No Heat

Hi,

I have forced air, and the heat is blowing cold air. The thermostat keeps jumping from 61 - 65 - 61 - 69 and back to 61 with the blower keep blowing cold air. The blower won't blow at all with the thermostat set to auto but when I switch it to on it will turn on and just blow cold air with it set at 75. The pilot light is lit on the boiler and I have hot water. What is causing the cold air? The Thermostat?

GFrazier
Re: No Heat

The new thermostat did not fix the problem

dj1
Re: No Heat

Check gas supply. If OK, it could be the gas valve, which is a job for a pro.

keith3267
Re: No Heat

If this is a boiler that provides hot water as well as hot air, then either a circulating pump is not working or you have a solenoid that is not working.

canuk
Re: No Heat
GFrazier wrote:

Hi,

I have forced air, and the heat is blowing cold air. The thermostat keeps jumping from 61 - 65 - 61 - 69 and back to 61 with the blower keep blowing cold air.

Being forced air heating , it's recycled indoor air ( at the inside ambient temperature ) that you are feeling.

Quote:

The blower won't blow at all with the thermostat set to auto but when I switch it to on it will turn on and just blow cold air with it set at 75.

With the thermostat set to * Auto* or *On* only controls when the blower turns on.

Set to *On* you are manually turning on the blower to run constantly until you move the swith to *Off* or *Auto*.

In the *Auto* setting -- only when the heat source is fired and reaches a set temperature ( at the heating unit ) is when the blower would turn on to circulate the heated air. At the point when the indoor temperature reaches whatever you set the thermostat is when the blower shuts off -- automatically.

In other words -- turning the switch to *On* won't turn on the heat -- just the blower

Quote:

The pilot light is lit on the boiler and I have hot water.

Is this a hydronic forced air system --- system that uses hot water circulated through a water to air heat exchanger located in an air handler ?
If so, then it sounds as though there's an issue with the water circulation components or the associated controls or possibly some wiring.

Quote:

What is causing the cold air? The Thermostat?

While it's possible a thermostat is faulty and can happen from time to time -- more often than not problems are usually elsewhere --- as you found.

No offense , it doesn't sound as though your knowledge of heating systems lends you doing any further troubleshooting.
My advice would be to call a professional to troubleshoot and repair the heating system.

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