Pitching problem

beanie10

A mate has a problem with his heating system. Its a new house (3 years old) 1,600 sq feet bungalow 12 radiators.He has a solid fuel stove an oil burner. The stove on its own works fin as does the oil burner. The problem starts when he has the two of them on together, water flies outn the overflow. To solve this we removed the motorised valves and left them manually open, except for hot water valve. We also turned all the thermostatic up to max and the problem still happens. Every time it happens the system takes in air which has to be bled manually.
The only thing that looks strange is 4 or 5 non return valves on a foot lenght of piping.
Any suggestions are welcome.

Billy Bunting

No thermostatic control over the stove, turn the stat on the oil boiler down.

Buford T Justice

Is the stove heating the water, rads or both??

beanie10

There is a pipe stat for stove set to 55. Its the radiator valves that set to max. The stove is heating the hot water and radiator through pipe stat.

Billy Bunting

All your stove pipe stat is doing is turning on your pump when your water heats, it ain't gona stop your mate throwing coal in it. .

celiam

did you check the ballcock in the water tank in the attic? it might need replacing

Buford T Justice

I doubt it. I'd say its more likely due to the fact that you have a boiler and a stove heating water, which would cause a larger amount of pitching. Turn the stat on the boiler down to the same as the stove pipestat.

DoneDL

its a pipework issue ot the motorised valves are affecting the safe working of the stove, a quick fix could be using a second stat to turn off the oil boiler when the stove gets up to temperature but set lower than the stove stat.