Potterton Puma 80E Sticky Diverter Valve

[GeeTee]

Bit of a problem - xmas eve as always

On CH my Potty Puma 80E only runs for about 30 seconds before switching off. A couple of minutes later it fires up again... for 30 seconds or so. The closest 2 or 3 rads to the boiler get hot, lukewarm for the next couple then cold for the other 2 furthest away.

Suspecting the diverter valve was a bit sticky / partially opening I gave it a tactical tap with a hammer - a voila..... heating stays on

Until.... the heating goes off for any length of time or the DHW is used... then back to the start until the tactical adjustment is made as above


Any thoughts as to whether:

a. this is likely just to be the wax head gone 'weak' (i.e. do they tend to either just work or not, or can they go weak?)

b. the valve itself is gummed up and could be stripped and cleaned

c. the valve needs replacing entirely

d. would it be worth draining down and chucking some X400 (or the like) in the system - would this clean any rubbish off the valve??

Can't find anywhere open this am for parts otherwise I'd chuck a new wax head on it to see if it helps. But I could pick up some X400 at B&Q if it might help!

Thanks for any advice... and Happy Christmas!

Cheers
Graham

 

[Agile]

Its probably the wax head gone weak coupled with a little dirt.

Putting chemicals in will possibly help but it probably needs the wax stat changing.

We stock spare parts in NW London and could by arrangement help anyone even on Christmas day although its not exactly the expected way to spend Christmas dismantling a boiler!

Tony

 

[GeeTee]

Thanks Tony.

If I can keep it running with just tapping the valve from time to time, I'd rather do that over xmas.... s*d's law says if I try stripping it down to change a part I'll end up with a totally non-functional system for some reason and that really won't go down well!

You know how it goes... swap the wax head... then it leaks because the o-ring is slightly squished or something... and no way to get a replacement!

I'll try and get on it between xmas and new year. I might be bothering you for parts mind, I'm just over in Chorleywood.

Cheers
Graham

 

[ChrisR]

Try a heat gun on the front end of the diverter.

 

[gazthepottertonengineer]

Try a heat gun on the front end of the diverter.

Being careful not to st fire to any wires around it

Also check yo havent got any leaking Hot taps

 

[ChrisR]

On second thoughts, Puma - just set fire to the boiler?

 

[GeeTee]

ChrisR wrote:

On second thoughts, Puma - just set fire to the boiler?

You don't know how many times I've had that thought! It really does seem to be poorly put together from reject parts.

Enjoy your turkey

Cheers
Graham

 

[idealmaint]

went to one of these last week...on for 30 secs off for 30 secs. Water temp was getting nice and hot then running cold. Turned out to be a split in the hose to the air pressure switch....which was pretty much the very last thing i checked...could be the mod board or thermistor problem or circ problem

Merry christmas everyone

 

[ollski]

It really does seem to be poorly put together from reject parts.

No, that was the potterton lynx even the pumas aren't that bad.