Hot Water Woes

[stuart_fyfe]

For a while now our hot water has been... not so hot

It started one night, I went in the bathroom and there was water sprayed everywhere (from the boiler). We called the British Gas man in to take a look and he got it working, but the HW hasn't been well ever since.

I've been scanning through the forums and have picked up the rough jist of how the thing works... sort of

The boiler is a gas combi Potterton Performa 24

The boiler is set to CH/HW. When a hot tap is turned on the boiler starts and everything looks good... but the water is only luke warm at best. I've noticed the CH pipe getting hot too (heating is not on)

From what I've learnt in the last few hours... it could be the 'diverter valve' or the 'DHW HE'. Or possible not.

Sorry for the long post, I wanted to get as much info as I could to you guys. P.S. I have never been inside a boiler so much guidance is needed.

Hope you can help,
Stuart

 

[chrishutt]

it could be the 'diverter valve'

 

[stuart_fyfe]

Ok, so you are saying that is probably the diverter valve?

Is it hard to take out a diverter valve?

 

[chrishutt]

Is it hard to take out a diverter valve?

It depends....on your knowledge and ability mainly. You need to study the manual for your boiler, which you can probably download from the Potterton site (or view at Partsarena.com/baxi/). Then you must answer your question yourself. If changing the diverter valve involves dismantling any part of the gas side of the boiler, this should only be done by a Registered Gas Engineer.

 

[stuart_fyfe]

I've taken a look inside the boiler. I tested the microswitch which I overlooked, but worked fine.

I have no problem with taking the parts out to have a closer look, I just cant figure out how to drain the water out of the boiler. I've read that manually opening the pressure relief valve could cause it to leak slightly.

Could a wack with a spanner fix it do you think? Or are they particaully fragile?

 

[chrishutt]

I just cant figure out how to drain the water out of the boiler

You haven't read the manual then?

 

[stuart_fyfe]

Right... I located the drain point in the boiler!

So to drain the boiler I'd have to close the heating out and return and the water inlet. Then drain the water out of the boiler??

Then when I fill it again...
turn the gas supply off at the bottom of the boiler (to stop HW getting hot)
Turn on the water inlet & turn on hot taps
open the filling loop & CH pipes
Then wait until 0.5 bar and close filling loop

Does that sound right? Anything I might have missed?

Cheers for your help

 

[chrishutt]

A few points......

1. Turn off the electricity supply to the boiler before draining. No need to turn off the gas - nothing can happen without electricity.

2. Using the flow and return CH isolating valves below the boiler can result in them leaking a little afterwards - depends on age and make of boiler - don't know about Performa - but you have been warned.

3. As well as closing the mains inlet valve, open hot taps to relieve pressure and help drain hot water side of boiler.

4. Try to avoid using Pressure Relief Valve to drain the boiler - once they have passed water they are inclined to leak a little forever afterwards.

5. Refill CH side of boiler to about 1.0 Bar (or more if your boiler is at the bottom of a system spread over 3 or more floors).

6. Make sure you have followed instructions for venting air from the boiler before running afterwards. Check automatic air vent in boiler - is plastic cap loose (which it should be) to allow air to escape?

 

[stuart_fyfe]

I got down to taking the valve out but could not disconnect the CH flow pipe from it as my adjustable wrench was a fraction too small

I put it all back together, put the pressure back upto 1 bar (the automatic air vent was loose to allow air to escape).

I turned the boiler on and now it wont ignite. The flow switch activates the microswitch, and then the other microswith is activated (which i assume is for switching to HW). The pump and everything starts but no flame. I give up!

Time to get in the CORGI me thinks

 

[chrishutt]

Did you perhaps accidentally disconnect the ignition lead(s) when working on the boiler? Often happens to me, so worth checking.

 

[stuart_fyfe]

I'm not sure what it was... but now it is working fine

The hot water comes on without the CH pipe getting hot, havent tried the CH yet. Hopefully it will work too.

It still makes some weird noises, but at least I can have a shower!

Cheers for you advice, I think next time I will leave it to the pro's.