Boiler or Thermostat

[Jude H]

I have a very old thermal store (for dhw & ch) which works fine for ch but is sporadic for hw. Had the cylinder descaled in case that. Last week lots of hw, boiler coming on & off as required, this week - no hot water & boiler not coming on to heat. Switched thru timer controls (from timed to off back to timed) now boiler comes on but is on the whole time the timer is on.... does this sound like a thermostat issue? The man who descaled cylinder suggest the thermostat was stuck in place so any ideas on how to remove it without breaking itn(as cannot afford to replace cylinder) thanks

 

[moonlight]

Is your thermal store the Gledhill with a panel on the cylinder with a clock at the top and a dial you can turn to summer or winter?

 

[Jude H]

No it's much older than that (sadly) - I think it was made by heatweb..... when it works it's fine it's just so temperamental

 

[moonlight]

Have you got a picture?

 

[Jude H]

My one is behind loads of random shelves - it looks very much like this one (except mine has no emersion) & the thermostat doesn't have a dial on it (best internet trawling I could do)