Potterton Puma 100 problem and pressure for shower

[adj]

Hi Folks

I'm having trouble with my puma 100. Last night I flushed the toilet and turned on the hot tap in the bathroom only to hear the boiler in the kitchen making a huge racket. The boiler had been providing central heating continuously for 24 hours. (It's cold up here) The pressure relief valve had opened - I assume the water was boiling - and I shut the system down. Once it had cooled I tried to repressurise the system by opening the fill loop but water continues to come out of the prv (I assume it's the prv. It's on the top left of the unit if you have a puma 100). Am I right in saying the prv should close by itself when the pressure reaches a safe value?

It may be unrelated but since I moved into the house a couple of months ago the shower working from the puma 100 runs cold after a few mins every time I take a shower. It runs hot again 3 or 4 mins later.

The house is an unusual design. The shower and bedrooms are upstairs. Downstairs I have a couple of radiators. On a middle level, halfway between the other storeys is a kitchen and hall with the boiler and a couple of radiators. From memory the pressure was way above 1 bar for the last 2 months since I moved in. I guess it was more like 2 bar. Anyway anyone any idea what I should set it to if I can get it repressurised?

Brrrr

ADJ

 

[chrishutt]

You should set the pressure to about 1.0 Bar. Your PRV may not close properly once it has released water - common problem. Try manually opening and closing it a few times (twist red knob) - it may bang violently, but it sometimes cures the problem. Otherwise you'll need a new PRV.

 

[gstens baxi]

The one at the top left is the auto air release. The flow hot water flow switch may have stuck which will over heat the boiler this may only need adjusting but probably will need to be replaced, as will the auto air release..

 

[adj]

Hi Chris

Thanks a lot for your help. I twisted the red knob a few times as you suggested. The one to the right in the photo http://www.7seals.co.uk/assets/images/puma 100e/CRW_5832-01g.jpg

That seems to have done the trick. I've set the pressure to 1 bar too http://www.7seals.co.uk/assets/images/puma 100e/CRW_5836-01g.jpg

The heating is now back on and the hot water works too.

I'm still not sure what caused/allowed the water to boil though.

By way of thanks and to help others who might have this model I've put a few photos up on some borrowed webspace at
http://www.7seals.co.uk/assets/images/puma 100e/

I've never put anything on the web before so sorry if it's not easy to browse. There is a wiring diagram and a fault finding guide which was stuck to the boiler in case other users find them useful. I'll take them down in a few days though as it's not my webspace.

Thanks
Andy

 

[adj]

Hi gstens baxi

Thanks for your help. I have a puma 100e not the 100 as previously stated. To help other users, the part where the water was coming from was at the top left of my boiler. I've put a picture here http://www.7seals.co.uk/assets/images/puma 100e/CRW_5805-01g.jpg

Is this the auto air release you were talking about?

As I said above the system's seems to back in reasonable working order but I'd still like to know what caused the boiler to overheat in the first place.

Thanks for your help.

Andy

 

[Agile]

You have already been told above that the DHW flow switch had become stuck on after hot water usage ended.

It will need fixing or replacing and possibly the diaphragm unit if its been leaking at the shaft gland. Otherwise the problem will repeat itself again soon!

Tony Glazier