Turning boiler ON after long period

[MeldrewsMate]

Isn't that a Potty Puma? If it is it'll have the name written on the front (and I have several dusty spare bits in the garage too). If you've tried plugging in, etc., then take a camera/pen/paper next time, and jot down some boiler details and some facts.

@yartin, there is no point turning on the gas until the boiler makes some sign that it's alive.
Make sure there is a 3A only fuse in the plug.
Have a competent person disconnect the boiler's pump electrically. The Puma (if that's what it is?) hasa CP pump, and I've known a few that have windings leaking to earth.
Plug it in and see what happens. Are you certain the MCB trips....not the board's RCD?

 

[yartin]

Isn't that a Potty Puma? If it is it'll have the name written on the front (and I have several dusty spare bits in the garage too). If you've tried plugging in, etc., then take a camera/pen/paper next time, and jot down some boiler details and some facts.

@yartin, there is no point turning on the gas until the boiler makes some sign that it's alive.
Make sure there is a 3A only fuse in the plug.
Have a competent person disconnect the boiler's pump electrically. The Puma (if that's what it is?) hasa CP pump, and I've known a few that have windings leaking to earth.
Plug it in and see what happens. Are you certain the MCB trips....not the board's RCD?

Yes PUMA 80e. You are v good...
I plugged in boiler and gas on, boiler switch is ON, Central heating switch to constant, turn hot water tap nothing happens only a click from inside boiler. Turn heating ON from Drayton timer (pic below) and the fuse trips in Consumer unit, its the first from the right labelled BENCH (pic below)
Panel shows "low system pressure", but gauge shows over 1 bar, why is that?

 

[Madrab]

Firstly it's not the MCB that's tripping, that's an RCD. As suggested there could be a fault condition leaking to earth and it's tripping the RCD.

Secondly, tap the pressure gauge for the boiler and see if it moves, if it doesn't then the boiler is way over pressurised ..... more than 1 bar .... try more than 3, way too high if that's reading properly. You may be getting a faulty low pressure light because the sensor's goosed, again probably because it's been inactive for 10yrs. I would also expect the dump valve to have release some of that pressure though, unless the fill loop has been left open or the valve has jammed.

Parts are getting rare but they are still obtainable, even a PCB, though they aren't cheap. Cheaper than a new boiler though.

I would suggest you get an engineer that is happy to spend a little time diagnosing the problem and not one who obviously hasn't a clue, tells you the parts aren't available when they are and suggests a new boiler. As the boiler is lighting up and clicking I wouldn't be looking at the PCB quite yet either.

 

[MeldrewsMate]

So you've had a tenant renting your industrial/commercial unit for 10 years on a full repairing lease; may I suggest that this wouldn't be a bad time to put your hand into your pocket and replace that 25 years old (or older) boiler; any new tenant may knock you on the rent offer or insist it's changed before signing, so it will be money well spent...

...but if you don't want to do that then get a(nother) RGI in to repair it; it may pay dividends to get one who is familiarwith the Potty Puma, of which there are two variants, permanent pilot or spark ignition.
I suggest you ask the RGI to:-
1. Disconnect the pump via it's integral connector (easy and quick to do), then repeat the electrical diagnostic of switching onthe heating.
2. Clear out the impulse pipe to the pressure switch, and replace that switch (relatively cheap component).
3. Check/replace the safety relief valve.
4. Recharge/replace the expansion vessel.

In summary, it is reasonable to suggest that the expansion vessel has failed in one of several ways, the tenant has become tired of regularly topping up the pressure and has left the filling loop valve(s) open, leaving the relief valve to operate regularly, and possibly fail to close properly. The pressure switch may be a secondary casualty, and leaking also.

 

[yartin]

The tenant turned boiler of from day1, used the space for storage, there are split heaters/coolers.
Why not repair if cost around £500?! Parts available, pump £130, refurb PCB £28...etc.
I have a guy coming tomorrow, see what he says.
There are no leaks or water marks.

 

[ianmcd]

you would be better putting the £500 towards a new boiler, if it is indeed the boiler causing the problem, that boiler was a piece of shoite straight out of the box, another thing , you have a 2 channel programmer controlling a combi boiler, unusual but sometimes done, if you have another zone the motorised valve for that zone could be tripping the electrics

 

[Ihavenojob]

The hot water flow valve has probably dripped into the wiring terminal strip in the bottom of the boiler.

 

[yartin]

How about new boiler, new tenant moves in a again turns off the boiler for another 10 years?!

 

[ianmcd]

How about new boiler, new tenant moves in a again turns off the boiler for another 10 years?!

then simply write it into the lease that the new boiler is working and must still be working when the lease expires

 

[kidgreen61]

How do you know the gauge isn't stuck?
I would be bridging the LWPS to test.