My heating comes on with shower!?

Question

When we have a shower, the heating comes on. Does anyone know why this is. It's not ideal in July and costing a fortune.

Answer 1

you are using your hot water boiler furnace to heat your water it is quite common.have a seperate hot water heater installed to fix this

Answer 2

Do you have a mixer shower and is it the bathroom rad that heats up? If you have, then don't worry because it is the way older plumbers did the bathroom pipework. It is done so the bathroom warms uo when you are using hot water in there.

Answer 3

oh shower heating? i was thinking someother heat

Answer 4

The divertor valve in the boiler is passing,it's pumping out hot water to the radiators while it's heating the water for the shower.Turn off all the radiators at the valves until you call out a heating engineer to repair it.

Answer 5

is it a combi boiler? mine does the same thing, and no plumbers seem to be able to fix it,  they said i was lacking either a divert or bypass pipe? one or the other

Answer 6

Interesting one!

Foobix could be right when he says the diverter valve could be at fault - but you say it only happens when you use the shower!

If this is the case, and it does not happen when you use any other hot tap then, it could be this.

When the shower is running you are not using all the heat output that the boiler can produce because the mixer shower is blending it with cold water.

Therefore the boiler is dumping excess heat around the central heating to prevent it overheating.

My old combi used to do this but only the two rads closest to the boiler used to get hot.

If this sounds right - there's probably nothing to worry about.

What do you think Foobix?

Answer 7

You have a combi boiler and have incorrect settings

Answer 8

turn ur thermostat down for ur heatin should stop the heatin comin on with ur shower. the boiler will only make the noise of the water heating up through it when shower on.

Answer 9

Haha!  Looks like someone wired it up incorrectly.