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Boiler keeps coming on

Postby cwc2128 » Sun Oct 07, 2007 6:54 pm

Hi im new here ..
After the cold setting in i have finally got about fitting a new motorized valve in my system so now i have both hot water and heating, my question is this, when i re filled the tanks and switched the system back on the water would not heat ,i have a sealed cylinder stat with the metal strip , i had a look at it and discovered that when putting it back together the dial is on a spline with no flat edge ie it goes back on any way so not knowing what the temperature is, now i think the water is to hot, im getting in the 60's at the taps i believe it shoud be in the 40's ..
The other question is if i turn the stat on the cylinder to say 60 i hear the microswitch click and the boiler fires pump turns etc, if i turn it back to sat 55 it all turns off, if i leave it at 60 the boiler and pump run for say 5 minutes then switch off then switch on and it continues this cycle is this normal to switch on and off or should it just run untill its upto temp then switch off.
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Simply Build It

Postby htg engineer » Mon Oct 08, 2007 5:36 pm

It will run then cut out, as the water in the boiler reaches temperature.

The stat on the tank/cylinder controls the temperature of the hot water. there will also be a thermostat on the boiler, when the boiler reaches the temperature set at the boiler stat the burner will cut out.

Once the water in the boiler transfers it's heat to the hot water, the heating water will cool and it will bring the burner back on.

As for the boiler stat, you could try turning it one way to see if the water temperature cools down. If there's no way of setting the temperature, you could replace the cylinder thermostat.

When you say if you leave it at 55 degrees, the boiler stays off. Is this because the water temperature is at 55 degrees or more. Or does it just never come on.
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