hamworthy gas fired water heater - temp control thermostat

[rsparker1980]

gas fired hamworthy water heater - automatic ignition

went to look at above water heater problems with water temp. noticed that the phial or bulb connected to the temperature thermostat had snapped off. all that was in the pocket was the copper wire, which then goes back to control thermostat.

How will this affect operation. i know that when phial is heated vapour expands which then in turn moves bellows connected to a switch which closes to turn off gas solenoid when required temp reached.

i know temp control stat needs replaced, but with the phial off will it just mean the heater will never fire.

 

[45yearsagasman]

Do a continuity check on the thermostat connections and that will tell you what the stat does with a broken sensor. Normally what happens is contacts open when vapour expands and opens contacts to stop burner. In a broken state it may never shut the boiler down resulting in overheat. You are not very forthcoming with all the symptoms. Are you RGI and is this commercial?