Ariston 210 STI Indirect Cylinder thermal cut off

[Petefinny]

Hi guys I'm havin a problem with this cylinder, not dealt with these for a long time, what's the best way to check the thermal cut off device in these?

 

[SJB6]

Can you be more specific, whats the problem exactly and when is it happening?

 

[Petefinny]

The 7 bar temperture and pressure relief valve had opened up and was emptying, i checked the thermal cut off by opening it up and turning the temperture up and down with a flat and it cut out so i new was sound, i took out the valve and it was rotten and corroded so replaced and all was well, jobs a good un

 

[SJB6]

Cool.

When you say thermal cut out i take it you mean cylinder stat themal cut out? I dont think they are adjustable (cant remember exactly but think they are set higher than cylinder stat ie. 90 degree's C) but if i was having one trip out then i would dump some heated water out through the combined 7 bar and 90 degree's C temprature release valve into tundish and test it with a thermometre, its temperature would tell me where to look next. If it's corroded, you replaced it and it's fine then cool.
Unfortunately for you i got a couple brand new spare Ariston cylinder stats with thermal cut out, lol.