why does my central heating come on when i switch the hot water on?

Answer 1

if your plumbing installation has a cylinder in an airing cupboard and a boiler ( not a combi) it is most likely the motorised valve jammed open. ( quite common callout in sept/oct when weather turns they either jam open or not open at all) usually because the motor hasn`t been needed to open valve throughout the summer month.and it sticks

or your programmer is stuffed and is sending power to the heating motorise valve when its not ment to

either way it. can only be one of the two.
if its the 3 port valve or the programmer as a rough guide you`ll have a bill for about £150 ish

Answer 2

It may be that the furnace unit also heats your hot water. I have a high efficiency system by Amana that is connected to my hot water tank. The furnace pumps a heat transfer solution (basically antifreeze) from the burner to a heat exchanger for the central heating. The water heater, which is ten feet away, is connected by copper pipe to a bypass valve near the pump in the furnace. When you're using hot water and the water temperature drops in the storage tank, a thermostat on the tank turns on the furnace and activates the bypass valve. The heat transfer solution now circulates through a heat exchanger in the water tank, instead of through the central heating. However, the blower that circulates inside air does not come on, because all the heat from the furnace is being diverted to the water tank.

Answer 3

Klamidia is nearest. If it is a problem that has only just started, the most probable cause will be the three way valve. If a plumber has changed the pump, you have certainly paid for unnecessary work. If either part is working the pump cannot be faulty. Would tend to get a new three port valve. It is possible to just buy the head, but, depending which make it is, i.e. Honeywell, some use a rubber ball to divert the water and this can sometimes stick, so it would pay to change the whole thing o be on the safe side.

Answer 4

It is not rational that the two are related unless:
- The central heating also heats the water
- The water pipe runs through or penetrates the heating ducts (if forced air) or is near the thermostat
- The water feeds the central boiler (if a hot water system)...in such a case, the cold water enter ing the system would kick it on, but still not sure why running hot water would affect it, unless there is a connection

I would suggest tracing your water pipe bace from the water heater and see if it is nearby the heating system

Answer 5

Mine used to do that.

We have a very old house, with a very old heating system which ran the central heating and the hot water off the same system.

When we turned the hot water on, although we didn't switch the central heating on, we still got hot water in the central heating system by convection. The only way to stop the house getting like a sauna in the summer was to turn all the radiators off.

We've changed ours now.

Answer 6

Don't know exactly what you mean. Do you mean by ''switching the hot water on'' you turn on an electric switch? Your hot water nay be supplied by your heating furnace. Some boilers have a separate hot water coil but the furnace still turns on to heat it. The switch may have been labeled ''Hot Water'' so that in the summer months the furnace (hot water) could be shut off when not needed. If so and it's winter time leave the switch in the on position.

Answer 7

the heat in your boiler heats the water that is stored in your hot water tank when you turn the heating on the pump forces the water to move along the pipe work heating the radiators,heated water that's in your tank can make warm the pipe work and radiators mainly those nearest to the tank,you can fit a control to your radiators or just turn the valve down

Answer 8

chances are your divert valve is letting by try changing the synchrone motor inside the top cover but be sure to switch off the electric supply first if this doesn"t work then you will have to change the whole diverter valve ps .it will be the same if you have 1 or 2 valves i hope this info is helpful

Answer 9

If this a new fault then your 3 port diverter valve could be sticking, if it has always been like this then it is the way it was plumbed in.

Answer 10

diverter valve letting by