My central heating is coming on with my hot water when its showing off - any clues?

Question

My central heating is coming on with my hot water when its showing off - any clues?

Answer 1

It really depends on the system you have as different systems= different repair or diagnoses.

It you have a Y plan or S Plan system with boiler, cylinder, and tanks in the roof then one of the valves is stuck in the open position. With the Y plan, it may be that you have no ' hot water off' in you wiring. Was anything changed recently? eg parts?

If so then wiring fault, if not then try finding the systems fused spur. This turns the power off to the programmer and all other ancilleries. Then try turning on. It just be be that the valves is sticking slightly. 240v off and then on after 10 seconds can sometime 're-set' systems. Bit like Control-Alt-delete on a PC

Best of luck!!

Answer 2

I agree with anthony 3 way valve stuck open,give it a whack with a hammer and a bit of wood

Answer 3

Turn the main room thermostat down to about 10 degrees.  Then only the hot water will come on, or check the boiler controls, there may be a switch to turn the central heating off.

Answer 4

Motorised valve stuck, or ceased.

Answer 5

your motorised 3 way valve is stuck open

Answer 6

Tony B is right,the system has either 1 three port valve or 2 two port valves.The fault will be the same on both types of valve,either the motor has jammed allowing the hot water meant to heat the water tank being pumped round the radiators or the plug that stops the flow of water to the rads is passing.

If the motor in the 3 port or heating 2 port is turning then the whole valve will have to be replaced.

Answer 7

Sounds like your three port valve has gone faulty.

Check if it has a manual override on the top and drive it manually, then start the boiler again.  If it still happens then the seal inside has gone, if not its propbably the motor on the valve.

Either way sounds like a drain down and replace to me

Answer 8

If you have one of those auto-switches which switches from heat to water, then it's possible it may have become jammed.  I have a lot of experience of this and have found the best way of dealing with it is to turn all the radiators off during summer.  How?  Switch on your hot water so that your rads start to heat up.  Check each rad individually, put your hand at the pipe at the bottom first on the right and then to the left.  Which one is hot?  Turn off the hot tap on that side.  Do this to each rad.

You'll have to do the reverse again come the cold weather.