potterton puma 100e diverter valve

[pat.pai]

Hi
I am having a problem with my boiler,when it calls for heat it fires up 15 to 20 seconds then cuts out and 10 sec latter it fires up again,and there is a loud hissing noise from the boiler it cycles like this for half a dozen time before it settles down,and it takes quite a time before it reach,s temp on room stat.
pat.pai

 

[Agile]

Its not clear exactly what your problem might be.

Things to check are:-

Does DHW demand switch turn off immediately demand has ceased.

Do you have any dripping taps or showers?

Is CH output set to match system? Thats the most likely cause and if so its only turning the pot on the PCB down to cure!

The diverter may well be slow to respond but if it gets there within a couple of minutes thats still OK.

Tony

 

[pat.pai]

Hi tony

DHW turns of immediately

No dripping taps

CH panel set points are not in use on this PUMA 100e model

could the fault lie with the expansion valve,and if so how can I check it

Pat

 

[ChrisR]

Could just be a slow pump. Is it more or less OK on HW?

 

[Agile]

Things to check are:-

Is CH output set to match system? Thats the most likely cause and if so its only turning the pot on the PCB down to cure!

Tony

The CH setting is a black spindle on a potentiometer lower down on the main PCB. It needs to be set just above minimum so the flame is about twice the minimum size ( that assumes the minimum flame sixe is correct at about 10 mm flame height compared with about 40 mm at maximum. )

Tony

 

[pat.pai]

Hi Tony

I adjusted the CH pot and that did the trick so thank a lot.

Pat

 

[Agile]

Glad that I was able to suss that one out for you!!

Much cheaper to adjust the pot than change the pump!

It will also run slightly more efficiently and quietly and with less stress on the parts.

Tony

 

[baxpoti]

And how old is the boiler?

Adjusting the potentiometer to a lower setting will of course improve the problem, inevitable that a pump is required!

 

[pat.pai]

Hi
my boiler is ten years old could you tell me how i could check the large expansion vessel
pat

 

[ChrisR]

Even wth the heating output on FULL it shouldn't cut out in 15-20 seconds. Turning it down is NOT a fix! If it "settles down" that certainly wasn't the problem though the setting should roughly match the load. If the pump's working the rads should heat up evenly together - do they?

Pressure vessel is covered in the faq's - Boiler Pressure Problems covers how it works.

 

[Agile]

30 kW into a sluggish diverter valve is almost certain to cause "noises".

The real underlying problem is likely to be a sluggish diverter valve but with the CH properly set its likely to be some time before it has to be changed.

The problem is more noticeable when the incoming water is so cold.

Tony

 

[pat.pai]

Hi

could any one tell me how i can find FAQ as i an new to this forum and find i cant navigate to well iam looking for boiler pressure problems.

pat

 

[ChrisR]

Prepare to kick yourself
it's at the top of the section...

//www.diynot.com/forums/viewtopic.php?t=37170

 

[pat.pai]

Hi

your right i need to kick myself

i check the expansion vessel and air discharged from it so now i know the diaphragm is ok,so it makes me think it's the diverter valve could any one tel me the operation of this valve

pat[/u]

 

[ChrisR]

It's something to read up on - plenty of posts here, do a search.