Surely not just an immersion heater?

totsa123

ok, just tried this. With hot water on and lever in manual nothing happens. With heating on and level in manual pipe gets hot and boiler fires

totsa123

WiserMiser said:

Leave the immersion heater permanently switched off and the boiler controller set to hot water only.  Wait a few days and make sure you continue to get hot water.  That will prove that the builder was talking nonsense about hot water being provided only by the immersion heater.

Then set the room thermostat as low as it will go (so that there's no call for room heating) and wait a few more days.  If the water runs cool and then cold, that suggests the boiler controller has been mis-wired or is faulty and that the builder needs to fix it.

Thank you, our neighbour has also just confirmed that their hot water works fine, but they have their heating turned on constantly 

Flugelhorn

I suspect some mis-wiring - certainly doesn't look likely that the tank is not connected to the boiler. 

FreeBear

Netexporter said:

And get the builders back to insulate all that pipework.

And while he is there, give him a swift kick to the backside for fitting the most basic (and cheap) timer. The Baxi boiler is OpenTherm compatible, yet the timer only does on/off control.

Any half decent heating engineer would have fitted a programmable thermostat that allows for different temperatures throughout the day/week AND does priority domestic hot water - This means the boiler can dial back on flow temperatures when just doing heating and switch to a higher one when reheating the tank. Something like the Wiser would have cost about £125 compared to the £65 for the EPH R27 (plus what ever cheap thermostat was fitted inside). A missed opportunity there to provide you with an efficient system.

With a secondary circulation pump, I'm guessing it is pumping hot water around the house so that you don't get a delay when turning on a hot tap - Be mindful that this is going to waste a lot of heat, so pipes under the floors had better be well insulated.

totsa123

Thanks all for your help, very much appreciated. Has given me the confidence to tell the builder they are wrong and get things sorted!!