Hot water temperature

gavinp

Hello.

The temperature of the hot water coming out of our taps seems to have become much hotter recently so I suspect there is a fault with our heating system.

I think the system is conventional, a boiler, hot water cylinder and tank in the loft. The cylinder has a thermostat set to 60 degrees C but the water definitely seems to have increased in temperature...

Is it the thermostat that is faulty or could it be something else as well ?

Thanks

Gavin

espresso

The easiest thing to do is to back off the thermostat setting to say 50 degrees with a screwdriver. If your water still gets too hot, it is likely that the divertor valve is not operating correctly, which should shut off the heat to the tank when it reaches the desired temperature. I would guess that this is the most likely cause but you need to prove this.

gavinp

Thanks for the reply - I did try the thermostat at 50 degrees over the weekend but that didn't make any difference.

Is replacing the divertor valve a DIY job ?

Thanks

Gavin

espresso

Yes if you feel confident that you can do it. It is not always necessary to replace the complete valve as the motor part can sometimes be replaced with the valve still in situ. Sometimes they get gunged up inside and will work again after a good clean. They are easy to obtain from plumbers merchants and places like B & Q, Homebase etc. but more expensive. Personally I would locate one first and then see what you can do with it and then if necessary you can go any buy a replacement if you need one.

You may find some useful info here but due to the way that the website is constructed, you will need to navigate the site for yourself.

:cool:

gavinp

Thanks again for your help - the diverter valve has three pipes connected to it and a box on the top marked as a "Drayton Mid Position Actuator" with an electrical cable coming from it.

Are all three port motorised valves the same or do I have to get an exact replacement to replace the actuator box only?

Thanks

Gavin

espresso

The 3 port valves that I have replaced, have been made by Honeywell. If the physical size of a different make valve was similar, you could fit an alternative make as it would match the existing pipework. You would need the same manufacturers actuator to fit your existing valve.

Another webpage showing various makes of divertor valve.

oldagetraveller

Could the simplest option initially be to change the cylinder thermostat like for like as it could be that which is stuck calling for heat? However, I don't know in which switching position cyl. 'stats usually fail??? Also much cheaper at around £8 than a valve actuator.
Recently had similar myself but the other way round - no hot water - and it was the 'stat not calling for heat!