Club 80-90 Forums

Last year we bought a riverside bungalow out here on the Norfolk Broads. The property had been totally rebuilt from the ground up in 2005 so all appliances date from then or younger. There is an oil fired boiler which provides hot water and central heating but this is done as needed i.e. there is no hot water tank. The boiler has a rocker switch for Off, Hot Water or HW and Heating. There is no timer but there is a wall thermostat. Hopefully that's enough info. We have occasionally noticed that the radiators get warm even though the heating is off and the CH thermostat is set very low. Is this normal for this type of system? I remember years ago when we had a solid fuel boiler in an old property the bathroom radiator was always connected even if the heating was off, I think it was to mop up any excess heat so is that what is happening here?

Cheers

Paul

sounds like the diverter valve is stuck.....................if this is happening when the hot water is being run....you can get room stats that are programmable (act as a timer)

there will no doubt be a master of leaks along shortly to verify or shoot down in flames

mark

voodoopenguin wrote:There is an oil fired boiler which provides hot water and central heating but this is done as needed i.e. there is no hot water tank.

It's called a "combi boiler".

Is this normal for this type of system?

Nope. As Mark says, the diverter valve's probably sticking, especially if the place hasn't been used much. Its job, simplistically, is to point the water that the boiler's heated either round the radiator circuit or the hot tap.

I remember years ago when we had a solid fuel boiler in an old property the bathroom radiator was always connected even if the heating was off, I think it was to mop up any excess heat so is that what is happening here?

If there's only thermostatic radiator valves, then one rad needs to not have a TRV, so that the boiler isn't trying to crank out heat with nowhere for it to go. But with a combi, if there's no heating needed, just hot water, the rads should all be cold.

thats basically right.. All really depends on the boiler you have, do you have the name and model? Some diverter valves you can just change the innards, others you have to change the whole thing.

it is very very very very rare to have a combi oil boiler (ive never seen one). are you sure it doesnt have a water tank inside the boiler case? Name and model and i could tell you more..

the valve wont be sticking due to non use, rather it will have a bit of debris in it causing it not to shut properly

Thanks for the responses so far. Not at the property at the moment and not sure when we will be back but hopefully within the week as the grass will need cutting! I will return to this topic when I have more details of the boiler.

Thanks again

Paul

Hi
I agree with lloydy,never seen an oil combi boiler either. Never seen a system that does`nt warm a radiator or two when its supposed to be on hot water only. If its a combi it should only heat the water when you turn a tap on so if your radiators are getting noticably hot are you sure its not got a timer internally ? Swith the therostat to zero and turn on the taps you will see if the diverter is working. Rads get hot,its knacked.

Martin..

Finally the combination of going over to the riverside bungalow AND remembering to get details of the boiler came together. The boiler is a Worcester Bosch Oil Heatslave 12/14 and as far as I can tell the radiators haven't been coming on when they shouldn't so maybe if it was that valve it is freed itself.

Paul

If it is definately a 12/14 then its a combi.. well thats all i can find on the worcester bosch website.. if it all seems to be working just smile and forget about it

If it does it in colder weather, could be the frost thermostat set wrong or malfunctioning.