Hot water not too hot!

mparter

Recently, I've noticed our hot water isn't as hot as it used to be. If we have the heating on, or it's just been on, the water's not too bad but if the heating's not been on then the water's not very hot. I have a combi boiler which I'm not sure of it's age.

Any ideas of the cause?

bruce2110

the problem you are describing sounds like either the divertor valve is not operating correctly or the pump within the combi boiler could be on the way out. best advice would be to a qualified local engineer to have a look.

p.s. do you know the make and model of your boiler as this may give a better clue as what the problem may be?

mparter

Sounds ominous. It's a Worcester Bosch 240 (or 280). Any ideas how old these are? And how much roughly would it cost for either of those repairs?

bruce2110

right after some looking around on the net, i think this thread from another plumbing and heating forum should be useful to you. PLEASE NOTE HOWEVER, THIS IS FOR INFORMATION PURPOSES, AND ALL REPAIRS SHOULD BE CARRIED BY A QUALIFIED ENGINEER. SAFETY FIRST!!

hth,

bruce2110



...you may well find that it is the valve in the diverter valve that has failed. if you want to check that is the real problem then do the following.
1) switch the electricity supply off.
2) Remove the outer white cover - it lifts up to remove
3) above the Green plastic cover that contains the electrics you will find a cros head screw from the panel to the main body of the boiler there is one on each side, remove these and the panel swings down and away.
4) to the left you will see a round valve housing about 2" (50mm) in what appears to be brass on its end is a black switch Housing.
5 Look closly at the point where the black housing meets the valve and you will see a spring clip, using a small screwdriver carefully prise this upwards and as it comes away the swich mechanism will come off the valve head.
6) On the valve head you will see a small pin in the centre, get an assistant to turn on the hot water and this pin may or may not move When it works correctly it moves out quite a way, if the part is faulty it only moves a little.
7) Now carefully prise open the cover from the switch mechanism, it is only very thin plastic so do NOT force it or you will break it and have to renew this as well. You will then see 2 separte micro switch contacts, these are black plastic, with your finger press these in and you will hear a click, now ensuring that you have not pulled any of the cables off and that the pilot light is still lit switch the electricity supply to the boiler back on, get your assistant to turn on the hot water now using your finger press both of the contacts (you are not touching electricity) at the same time, you should now hear the boiler fire up, get your assistant to check that hot water is now flowing (may take a while).
You have now proved that the fault is in the diverter valve, you need to get the part (about £14 on e-bay) and fit it or have some one fit it for you.
If you wish to fit it yourself you will need to switch the power off and drain the central heating system (you need to connect a garden hose to the drain !!!! and run the black water outside into a drain) you need to drain the heat exchanger and then again carefully remove the screws at the front of the diverter valve replace the diaphram valve being careful not to damage any other gaskets and refit the front. Now ensuring that the drain !!!! is closed use the filler loop to refill your system. You will need to bleed the air out of all your radiators. If you are not confident then call a plumber in but find out how much he wants to charge and tell him what you want him to do. You do not want to pay for new heat exchangers etc when all it needs is a £14 part....

mparter

Thanks for that. I'm confident enough to do the troubleshooting but not the fiting of the valve. Any ideas how much a plumber should/would take?

Is this something that's covered by the British Gas Homecare 200 policy?

djohn2002uk

mparter wrote:

Thanks for that. I'm confident enough to do the troubleshooting but not the fiting of the valve. Any ideas how much a plumber should/would take?

Is this something that's covered by the British Gas Homecare 200 policy?

This will be covered by your policy. Same as ours. It's part of the boiler so is covered.

saltgrass

turn hot water tap on. If boiler ignites but water doesnt come through hot for a decent period of time. It is the divertor valve not working or just sticking.
If boiler ignites for just a short period or not at all. It is a thermister which needs replacing.Usually they are inexpensive approx £15.