Dual central heating system

Dakota Dan

I’ve oil and solid fuel heating, over the last few days I used the solid fuel and the last two nights I used the oil heating but now the oil heating is heating the water in the back boiler of the stove which it previously didn’t do I’ve even turned off the circulation pump for the stove but it continues to heat the water in the stove. Anyone know what the problem could be?

John.G

Probably the non return valve in the back boiler stuck open, locate the back boiler pump and you might see this NRV or it might be located in the back boiler flow (outlet) pipe,

Dakota Dan

https://www.boards.ie/discussion/comment/118693966#Comment_118693966

There are two electric valves one lights up when the oil heating is on but the other one never lights up when either the oil or solid fuel heating is being used.

John.G

These non return valves are "mechanical" it spring loaded to open only one way.

You should be looking for something like below, more than likely the poppet type but (if) the swing check type will be installed in the horizontal.

Poppet Type NRV.jpg

Swing Check NRV.jpg