Does anyone have advice on a back boiler?

INSPIRED

In our sitting room there is an open fire with a back boiler. We rarely light the fire because of the back boiler! The problem is that once the fire gets going, hot water pours from a pipe above our upstairs bedroom window; gallons of hot, steaming water are pumped into the garden - what a waste.

The pump for the system is under the floorboards by the fireplace. There is a radiator in the room above (our bedroom) which is fed by the back boiler {is not fed by the CH boiler} and it has a thermostat but I am not too sure if it should be kept low or high.

We inherited this sytem with the house and know very little about the workings of a back boiler.

Last night we lit a fire and I switched off the CW & HW water boiler in the hope that the water from the back boiler would filter through. Within in a hour the radiator in the room above was very hot and water was spouting from the pipe outside. Within about 90 mins we could hear strange gurgling sounds from the HW tank. After about 3 hours some of the upstairs radiators began to warm up - but by then it was time for bed so we damped down the fire and switched the CH & HW boiler back on. It was -6C and most of the house was feeling very cold.

I would be grateful for any advice from folk who understand the workings of a back boiler in a house with a CH & HW boiler. Please ask away if none of this makes sense!

ormus

the main purpose of a coal fired back boiler was to heat the hot water. the one single radiator was just a safety net. a heat sink.
it was never meant to be a CH system as such.
the overflow pipe should go into a feed/expansion tank in the loft. it was fairly common for this pipe to get very hot with steam coming out of it. sometimes extremely hot!
running a hot bath used to cure it!

if you have a normal CH too, then i would rip out the back boiler.
the rad upstairs needs connecting to your normal CH system.

i cant understand why the CH installers left it in place?

caleyles

Sorry Ormus - will need to disagree a bit - plenty of systems up here run on solid fuel combined with oil or lpg for people in the countryside. It sounds very much as if one rad is off gravity as you said but the op said some other rads were getting warm - This wouldn't happen if the systems weren't somehow connected. To the Op - do you have a Dunsley Back boiler or similar. and either a Dunsley neutraliser fitted or a twin coil cylinder. If that is the case it could possibly be the pipe stat not bringing on the pump to the rads therefore letting the tank overheat but as ormus says run a bath to cool the tank which will stop the overflow running and prevent any possible damage or mess.

Check to see if you have one of these fitted

http://www.firesonline.co.uk/acatalog/Dunsley_Neutralizer_Boiler_Link_Up_System.html

ormus

yes that is true, but they were not the norm. the system i described was very common.
ive seen whole estates (1950s) fitted with such a system.

caleyles

I assume you are talking about the small copper back boilers for water only - was still fitting them in council estates in the late seventies/early eighties where council houses had a coal firfe and little else. The larger back boiler systems are still fairly common up north as gas can not be fitted to all small towns etc because of the vast expanses of the highlands as against the number of people and with readily available wood etc are fitted in conjunction with lpg (expensive) and oil - though electric heating systems are becoming more commonly installed. Personally I'm hanging off changing my own boiler for a couple of years until I see how the new ceres boilers are going to work out.

http://business.timesonline.co.uk/tol/business/industry_sectors/utilities/article6788024.ece

INSPIRED

Thank you for your replies and apologies for delay but cold weather is causing power cuts.

ormus wrote: »

the overflow pipe should go into a feed/expansion tank in the loft.

We have always wondered why all that hot water is not channelled back into the system. It is such a waste and it is destroying the surface of that wall.

if you have a normal CH too, then i would rip out the back boiler.
the rad upstairs needs connecting to your normal CH system.

i cant understand why the CH installers left it in place?

We would like to have it removed but it all comes down to cost. Also, we are have some warmth and hot water during power cuts.

INSPIRED

caleyles wrote: »

To the Op - do you have a Dunsley Back boiler or similar. and either a Dunsley neutraliser fitted or a twin coil cylinder. If that is the case it could possibly be the pipe stat not bringing on the pump to the rads therefore letting the tank overheat but as ormus says run a bath to cool the tank which will stop the overflow running and prevent any possible damage or mess.

Check to see if you have one of these fitted

http://www.firesonline.co.uk/acatalog/Dunsley_Neutralizer_Boiler_Link_Up_System.html

I have no idea what type of boiler we have but will have a look for the neutraliser. Our house is old (1850) and a plumber's nightmare with pipes running all over the place, under floorboards.

The CH & HW system was added in the 1970s - until then there were coal fires in all the rooms and the back boiler. Not too sure when that was fitted. The CH & HW boiler is fed by oil; our remote village has no gas.

So, am I right in switching off the boiler when the back boiler is being heated by the open fire? Last night, I switched off the HW but left on the CH in the hope that it would pump some heat to the radiators.

Everytime the water starts gushing out into the garden I have to run upstairs and turn up the thermostat on the radiator that is linked to the back boiler. The waterfall stops but our bedroom becomes unbearably hot!

Strange thing is that this morning, the waterfull started and the open fire/back boiler had been off since last night! So that must mean that the contents of hot water tank must have been emptying into the garden but I have no idea how that can happen. I ran upstairs to turn up the radiator.....it was hot so must have been fed from the CH system.

All so confusing. We have asked for advice from various local plumbers but they take fright and run!