rayburn

[richardq]

I have a rayburn gd80 that heats the hot water and cnetral heating. even if the controls are demanding central heating the boiler will not run unless the boiler (water) stat on the side of the range is set to 80 degrees. any ideas anyone?

 

[OilLecky]

Sounds to me that this is the way that your Hot water / Central Heating controls system is wired. i.e. Hot water selection has to be on to fire the boiler and the central heating selection just diverts some hot water to the rads, either with just an additional pump or via a valve. Has it always been like this?
More information would help. How many circulating pumps / zone valves do you have? Do you have a hot water cylinder thermostat and a room thermostat?

 

[richardq]

thanks very much for the reply - its hard to say whether its always been the way it is now, i've inherited the problem, but it has certainly been like that for over 12 months. there is a 3 port mid-way valve, and 1 pump. there is a room stats and cylinder stat. So to clarify, the boiler does nothing unless it is set to 80 degrees. if the timer says HW only the boiler will still not start unless the dial on the boiler is set to 80-ish. it may indeed be a wiring problem. i just wanted to ask whether it was something that was wrong with the boiler specifically? seems weird to me . . .

 

[Biggles..]

Faulty boiler stat

 

[OilLecky]

It seems that it is as lcgs says, provided that once the boiler stat is set above 80 Deg then everything works normally. i.e. hot water and heating work OK.

These kind of thermostats are not that accurate when first manufactured and go even further out of calibration with age. Presumaby the boiler isn't getting crazily hot when the stat is above 80 Deg?

Try to find out if the thermosat sensing phial is located correctly and not just hanging loose inside the case. If it is located OK, you can fit get your technicain to fit a new one or just live with it if everthingelse is operating normally.[/b]