And another boiler not working question.

[neilrr]

On Friday morning my boiler, a Potterton Suprima, failed to ignite. Called a mate of a mate who is a proper gas engineer & who had replaced the PCB & red wire about a year ago. Despite 3 or 4 calls he hasn't appeared yet & we are cold. Judging from the number of posts on here about boilers he probably is very busy.

The thing feels like it's trying to start. When I press the heat & or HW advance orange & green lights flash alternatively, it fires up for a few seconds then shuts down. It does this cycle 5 times then stops & goes to flashing red light. Pressing & holding the reset button for 10 seconds gives two red flashes.

I actually have another complete matching Suprima for spares & want to know this - what bits can I transplant to try to get mine to work again?

 

[StevenN]

I would say its the PCB again. It was a common fault with these boilers and a lot got fixed under goodwill when quite young.
If the PCB was old stock it might be of the same poor quality.
A new one may last longer.
I don't think your guy will get much joy complaining though

 

[neilrr]

It was the replacement PCB part # 5111603, the one that's meant to be bulletproof.

The original one was just a board, this thing is a big cassette type thing.

 

[Dieselman]

It could be the thermocouple not reporting the gas has ignited so the boiler shuts down again.

 

[Rory]

.. it fires up for a few seconds then shuts down.

Does the gas actually light, or do you just mean the fan runs?

There's a guide to the new PCB indicators here: Gas Central Heating Blog: Potterton Suprima Orange Light Flashing

 

[Mr. B]

It could be the thermocouple not reporting the gas has ignited so the boiler shuts down again.

That's fantastic !

I going to report my findings to my colorectal surgeon.

 

[neilrr]

Does the gas actually light, or do you just mean the fan runs?

There's a guide to the new PCB indicators here: Gas Central Heating Blog: Potterton Suprima Orange Light Flashing

I assumed the noise was the flame firing up but perhaps it isn't. Now that I look through the little circular observation hole I don't actually see any flame.

The 2 red flashes I mention in my opening post seem to indicate ignition failure.

 

[Rory]

I assumed the noise was the flame firing up but perhaps it isn't. Now that I look through the little circular observation hole I don't actually see any flame.

Do you see it sparking as it tries to light?

To be honest it could be lots of things, but the red lead you mention is a common failure - although I changed mine at the same time as the last PCB and the original ignition wire, which also doubles to send feedback that the flame is established, was in perfect condition.

It seems the new PCB is no more reliable than the old one and "the internet" says it's almost always the PCB at fault on these. I've had one new one and one refurb but I'm still on the old style.

ETA: There's quite a good guide here: http://www.ebay.co.uk/itm/POTTERTON-SUPRIMA-30-100-REPLACEMENT-PCB-GUARANTEE-/290802797660

 

[neilrr]

Can't see any spark.

 

[Peter DLM]

The last PCB I installed in my Suprema has lasted 6 years and counting. The latest one works quite nicely, the first 'updated' PCB only lasted 12 months. The boiler is now 13 years old.

They're simple to fit yourself, you aren't going near the gas supply so you wont be blowing yourself up.

 

[neilrr]

No call from boilerman yet again today.

I took the metal cover off to have a look.

The fan is spooling up & I can hear the spark igniter clicking (?), presumably trying to light the gas, but I can't see any spark.

Reading through the internet I think it's unlikely to be the PCB. Unfortunately it could be any number of other things from the air pressure switch to something as simple as a bad connection.

 

[lxi]

No call from boilerman yet again today.

I took the metal cover off to have a look.

The fan is spooling up & I can hear the spark igniter clicking (?), presumably trying to light the gas, but I can't see any spark.

Reading through the internet I think it's unlikely to be the PCB. Unfortunately it could be any number of other things from the air pressure switch to something as simple as a bad connection.

I'd guess at the air pressure switch - easy swap on mine (different make) - it's also probably the cheapest thing by far to try

 

[Rory]

No call from boilerman yet again today.

I took the metal cover off to have a look.

The fan is spooling up & I can hear the spark igniter clicking (?), presumably trying to light the gas, but I can't see any spark.

Reading through the internet I think it's unlikely to be the PCB. Unfortunately it could be any number of other things from the air pressure switch to something as simple as a bad connection.

It won't be the air pressure switch - that must be OK otherwise the ignition sequence won't start.

It could be as simple as the red lead has failed, or the spark electrode. Or it could be the gas valve not opening - did you do the check in the eBay link to see if you can smell gas?

 

[stevieb15]

Why don't you just phone Heat Team 08443352266 or get an alternative heating engineer off the internet.
I can never understand why an amateur would try to self diagnose a device with many of the characteristics of an unexploded bomb

 

[neilrr]

It won't be the air pressure switch - that must be OK otherwise the ignition sequence won't start.

It could be as simple as the red lead has failed, or the spark electrode. Or it could be the gas valve not opening - did you do the check in the eBay link to see if you can smell gas?

Can't smell any gas, but the vent is pretty high up so I'm not getting a great sample. I changed the red lead to a black one when the new PCB was put in. Is it possible that has failed after less than 18 months or so?

 

[neilrr]

Boiler guy has been & gone, it's the gas valve.

He's quoted "about £100" for a replacement but can't fit it before Monday so I'm on the hunt for a Potterton 8402550 if I can find one cheaper.

Ta to all for all the advice / suggestions etc.

 

[Rory]

Why can't you take the one off your spare Suprima?

 

[neilrr]

I asked him if he could do that & was told he can't use any second hand parts gas parts. Electrical bits, pumps, circuit boards are OK but bits that gas goes through are a no-no.

 

[neilrr]

There's a very wide price range on these babies. The most expensive I've seen for genuine parts BNIB is £225, the cheapest £46 (both + VAT). Luckily the £46 one is about 10 miles away.

 

[Rory]

I would try & grab that quick - even on eBay they're over £100 new and there are used ones at £45.