Help From A Boiler Engineer Please! Boiker Readings

[moggie 939]

Hello

I have a Potterton Promax Combi Boiler and it is working ok but....a week ago it lost pressure and would not start as the arrow was below the green segment 1 where it usually stays. I think the engineer who came out put some pressure in to it and it immediately came on and works fine except that instead of the arrow being half way up green segment 1 it is now at 12 o'clock in green 2.

Is this a problem - it works fine as normal but is noisier than before. Is this position still ok and safe?

Thanks

Moggie

[Buenchico]

As I see it, from looking at the manual, the pressure is a little high but not worryinly so. 

Take a look at Section 3.1 "Central Heating System Pressure" here:
https:/www.freeboilermanuals.com/assets/User_Manuals/Potterton/Promax_Combi_user.pdf

[nicebloke1]

2 is a little over the top but providing it's not in the red all is fine, normally thet aim for 1 and a half. But pressure will reduce when boiler cools down and may loose a little pressure over the coming days.

[nicebloke1]

By the way, if you have a massive loss of pressure again over the next few days, ask to have the valve replaced on the pressure vessel. The valve is no different really to a car tyre valve, but it may be leaking pressure, simple 2min job and 50p.

[Buenchico]

Let's see if my link can be made 'clickable':

https:/www.freeboilermanuals.com/assets/User_Manuals/Potterton/Promax_Combi_user.pdf

[Buenchico]

^^^ Apparently not!  Try this instead:
https://tinyurl.com/py7r24f6

[The Builder]

As said above, 1.5 is usually enough. I'd be more interested in why the pressure went down in the first place. It could be normal usage. They do need the occasional top-up, but the extra noise might suggest the pressure relief valve is operating and letting excess pressure escape (for safety purposes.) In use, the pressure may be rising when you're not looking. It would go into the red, and the PRV would blow off the excess pressure.  Keep an eye on it for the next couple of days. If there is a problem, it'll soon show up as the pressure would drop again and cause the boiler to not operate (as you've recently discovered.)

IF there's afault, it will likely be a ruptured pressure vessel, or a faulty PRV.

If it stays steady at 2, then all may be Ok.... but I'm more concerned about the noise.

[moggie 939]

Thanks for coming back everyone and sorry I did not reply immediately but I ticked the box for emails and I did not get your replies!

Thanks Builder and Nice blocke and buen chico. I think you are correct Builder and I will get the engineer out to look at it as it was always 1.5 and never so high! Never seen it go into the red but might have.

Will let you know after he has been

Regards

Moggie

[nicebloke1]

moggie. Trust me its dead easy to find out if your boiler is going well over the pressure limits. Switch on your heating, Leave on for 45 /60mins, then go and check the pressure indicator, if its in the red, there's a problem, if not, and the reading is 2 or even just over, its fine. If a boiler enters the red zone a pressure release valve comes into operation and releases that excess presure by the way of steam and hot water by an outside excit pipe that all combi boilers have fitted. so no need to panic.

[moggie 939]

Hello The Builder and everyone - I said I woiuld report back.

The boiler engineer came out and I explained everything and he spent some time sorting everything out!

He showed me a large red tank which he said was expansion tank and he drained out about half a bucket full of water from it - then he put in some sort of valve and reduced the pressure from nearly in red to mid first segment green.

He gave me a new t'stat for free and fitted it. The boiler kicks in quieter now and the heat bulds up faster in the rads and.......boiler  is about 50% quieter!

Thanks so much for your help everyone

Moggie