BackBoiler Pump Mystery

tm2204

Strange scenario.

House has OFCH with the circulation pump out at boiler & all working fine.

Also has a backboiler with the open fire but cant seem to locate the circulation pump for the backboiler. Not attached to pipes coming out beside fire and pipes then get buried and go under floorboards.

Backboiler currently can only heat upstairs rads because no pump to circulate to downstairs ones and if water in backboiler gets too hot the pipes start to 'hammer'.

My question is can I use the circulation pump out by the boiler to circulate the water to the downstairs rads when the backboiler is in operation & the OFCH boiler is not? I.E. have the pump running without the OFCH boiler running?

Will this do the job?

Tks

bbam

Older systems in two story houses had no pump fitted, we had one such system fitted during the 70's, like you say it will work fine as long as the rads are all on and the fire isn't too fierce to soon as it relys on the hot water to rise up and create a flow in the system...

It should be fine to run the pump out at your burner, it's worth a try and should create enough force to get the heat all round the house..

Alternatively you could get a pump fitted near the BB with a pipe stat which would sense the pipe from the BB getting hot and switch on automatically..

Sparkpea

the pump will likely be under the floorboards near the fire where you can see the pipes going under the floor. Is there a switch nearby? beside the fireplace or on the fireplace to control the pump? or it could be in the hotpress, or could be controlled by a pipestat in the hotpress. if you find the switch you may be able to hear the pump humming under the underfloor.

I wouldn't recommend using the pump at the oil fired boiler as there might be non return valves on anyway so it wouldn't work, plus if there is one under the floorboards and its pumping in the opposite direction then they will be pumping against each other. Look under the floorboards first, there should normally be a trap or a couple of boards that have been lifted at some stage..

tm2204

Thanks for the replies guys.

Deffo no pump as far as I can tell, no switch near fireplace or pipe stat in hotpress and have never heard any humming like you would expect from a pump.

Think the best solution is to fit a new pump & pipe stat but will try the OFCH pump as a test to see if it works (I can run the pump beside the OFCH boiler without running the boiler itself)

Pump might be under floorboards but theres a solid wood floor down and don't fancy messing with that.

tm2204

Tried running the pump by the OFCH boiler (boiler off) and it worked fine, heated all the rads downstairs. Only problem was the pump was running constantly as no thermostat to control it.

Happy now as new boiler stove going in next week and going to add a new circulation pump, pipe stat & electrical switch when getting the plumbing done.

neiphin

tm2204 wrote: »

Tried running the pump by the OFCH boiler (boiler off) and it worked fine, heated all the rads downstairs. Only problem was the pump was running constantly as no thermostat to control it.

Happy now as new boiler stove going in next week and going to add a new circulation pump, pipe stat & electrical switch when getting the plumbing done.

the pump should be in your hot press
the termostat needs to be near the out pipe from the fire, they will be beside each other

Buford T Justice

Make sure there's NRV's fitted so you don't heat the water in the ofch boiler too..

tm2204

Fingers McGee wrote: »

Make sure there's NRV's fitted so you don't heat the water in the ofch boiler too..

Isn't it the same water circuit?

Buford T Justice

It depends on the system.

Have you a separate coil in the HW tank to heat the water form the back boiler?

chinchin

It would be worth checking under the floorboards either side of the fireplace, that's where our pump was, there was a switch low down on a wall near the fireplace to control it too, no thermostat though.

tm2204

Fingers McGee wrote: »

It depends on the system.

Have you a separate coil in the HW tank to heat the water form the back boiler?

Yes, the OTCH boiler does heat the hot water as well as the rads.