I currently can only get hot water if I have the heating on. I'm told that the motorised valve needs replacing (or just the head) which looks simple enough to do myself.

If i switch my boiler on to 'water only' it doesn't fire up. Does anyone know if I replace the motorised valve that this will correct this.

Thanks in advance.

There's a rather helpful plumber on the BBS site if you sign up.

Big chest and massive boobs

[Link]

Thanks. Do you know whether a faulty motorised valve would stop the boiler from firing-up on 'water only' ?

Cheers all who have answered.

Hold the front page! I may be about to be helpful.

I had a similar problem where my central heating wouldn't turn off.

I needed to replace the top bit of the valve: [Link]

You should have 2 of these in your airing cupboard (providing you don't have a combi boiler) - one controls the heating the other the hot water.
On the back of each is a small piece of metal that you can manually slide over and it should slowly spring back into position. If one of them is jammed or really loose that'll be the problem.

You can replace the top part only without needing to do any plumbing (although it does have about 7 wires that you'll need to connect)
If you need to replace the whole unit that's a trickier problem.

My nephew on here (Eddie_Hitler) may log on for the first time in 10 years and be of help - he talked me through analyzing my issue and I managed to replace it myself.

PS: Turn the power off before you attempt to replace it. But if you don't can I have your semi-final ticket?

You fed me, you bred me, I'll remember your name.

Probably the diverter valve - try turning the power to the boiler off, then back on (listen closely). This resets the valve position, or at least it does on my Worcester (may have to do a couple of times). Had it happen a couple of times before where the heating wasn't used in the summer... . the valve gets jammed.

Hope this helps.

You'll either have 2 x 2 port valves (one for heating and one for hot water) or 1x 3 port Valve that does both.

If the hot water only works with the heating then it may suggest the motor on the valve isn't modulating. These can be modulated by hand. Give it a try.