Faulty thermostat in oil fired boiler

[Dave2heat]

Hi I have a domestic warmflow oil fired boiler (20 years old). The thermostat has ALWAYS been set at 60 degrees (On on VERY VERY cold days would it ever been turned up to 70 degrees).

Everything is working fine, although for the past month even with the thermostat still set at 60 degrees, the radiators and the hot water (out of the hot taps) have increased dramatically ! (although it is never scalding) The thermostat is still working as the boiler still cuts in and out as normal.

Is this the sign of a "faulty " thermostat, or is it even possible to replace this thermostat with on that has a lower setting, maybe starting at 50 degrees?

Any advice would be very much appreciated
Thanks

 

[Best]

Sounds like your thermostat is slightly faulty.
You cannot run the older type standard efficiency oil boilers at much lower than 60 degrees as the return temperature will cause corrosion.
That is why they tended to have a fixed minimum of 55 or 60 degrees.
If you upgrade to a new condensing oil boiler, the stat can run a bit lower, but remember your rads might need the system at boiler higher temperature setting to properly heat the rooms

 

[island fling]

Agree with BEST.
If you find it is not the stat it maybe that there is a fault with the 3 way diverter valve. I had one that was half open/ half closed & was producing VERY VERY hot water & Heating, thought it was the stat but when I returned to install the stat the 3 way diverted valve issue became apparent. That was most likely to be happening though as these folk had heating set to ‘Constant’ & the valve was getting the water very hot although it wasn’t going to overheat reset.

 

[SimonG]

Agree with BEST.
If you find it is not the stat it maybe that there is a fault with the 3 way diverter valve. I had one that was half open/ half closed & was producing VERY VERY hot water & Heating, thought it was the stat but when I returned to install the stat the 3 way diverted valve issue became apparent. That was most likely to be happening though as these folk had heating set to ‘Constant’ & the valve was getting the water very hot although it wasn’t going to overheat reset.

More of a combi problem that one. Store is sat at higher temp than heating. Can normally smell the heating when the 3 way is on the fritz.

 

[Dave2heat]

Many many thanks Guys for taking the time to reply and explain why I can't have a lower setting. The reason why I posted here, is that I had telephoned a local "heating engineer" and explained the problem, but he stated that as the burner was starting and stopping as the temperate increased/decreased, then the thermostat was working perfectly.

once again thanks

 

[island fling]

More of a combi problem that one. Store is sat at higher temp than heating. Can normally smell the heating when the 3 way is on the fritz.

Sorry mate, never ready the post properly....Thanks