hot water not hot, central heating works fine

[dafengche]

Hi, I've got a Powermax 135. Recently the hot water becomes not hot any more - about 30 - 40 degrees. I read the user guide and found the domestic hot water should be 65 degrees. Could anybody please point out what's the problem and how may I fix it? - Thank you, dafengche

PS. The central heating works fine.

 

[spacethegas]

"oventrop" mixer valve ?

 

[dafengche]

"oventrop" mixer valve ?

Thanks for your reply. What I guess is that there is a temperature sensor for domestic hot water and was set to 65 degrees. If so, maybe there is chance to adjust the setting or replace it. Is this correct? It seems I could not find a powermax 135 manual. Anybody has it?

 

[spacethegas]

the mixer valve is fitted right at the front it has 3 pipes going to it.
it mixes the hot water passing through the powermax & blends it with cold water to provide the correct temp at the tap.
this valve is adjustable by the knob on the top.
its very common for the guts within this valve to disintegrate.
if its removed you can usually see that it has failed.
if you do remove it make sure you have replacement 1" fibre washers.
& the valves are not cheap.

 

[dafengche]

Thanks. I will have a look soon.

 

[dafengche]

Hi, I opened the cover under the controller and found a cylinder with several pipes. Unfortunately the valve (possibly) for DHW is very close to the controller and can not be viewed fully. I noticed that when hot water (which is NOT hot) is on, one pipe (from the cylinder) to the valve was hot, the other pipe which I think the DHW outlet pipe was warm. Does this mean the problem is caused by the valve.

I uploaded an image at http://myweb.tiscali.co.uk/xyang/v.jpg

 

[spacethegas]

thats the kiddie.

the photo is the mixer valve (oventrop mixer valve).

the top can be removed with an allen key & the exposed knob can be adjusted to alter the h/w temp (when operating correctly).

 

[dafengche]

Thanks. Now I need to think about how to access the top of the valve. It seems that I have to remove the controller first. What is the allen key? Where to get it?

 

[spacethegas]

Untitled

• spacethegas
• 14 Aug 2008
• 1

allen keys.

 

[dafengche]

Thanks. It seems I have problem removing the controller which covers the valve. I will have a try again in the next couple of days. Otherwise I may have to ask for a plumber.