Glowworm swiftflow 100 No heat/HW

[anton07]

hi all.

the boiler is a glowworm swiftflow 100,around 12 years old and regularly serviced.

when on demand for either heating or hot water the pump and fan will run.You can hear the click at the air pressure swich but thats about as far as it goes,the main burner wont light.A few weeks ago the fan was jammed and wouldnt start.while I was up there, I sucked on the white tube from the fan to the A.P.S to make sure the A.P.S was operating anyway and the boiler lit up fine.I am wondering now if the A.P.S is faulty or if there is a problem with the P.C.B! grateful for any advice,thanx in advance!

 

[gasman26]

if the boiler fired when you manualy made the a.p.s switch this indicates the p.c.b is o.k
It sounds to me as if the fan is running slow (replace fan assembly) also check for blockage in the tubes from fan to a.p.s

 

[ollski]

You can bridge the aps for testing purposes.

 

[anton07]

I tried manually checking the A.P.S today though and it didn't work this time,it still clicked but the burner didnt light.I know the A.P.S can stil be nackered even if its still clicking but Im still wondering if its maybe the board.The voltage across the connectors to the A.P.S is only coming up at between 2 and 4 volts!!!

 

[Agile]

If the fan does not speed up with a demand for heat it could be a faulty fan but it might also be a faulty PCB.

Tony

 

[ollski]

The voltage across the connectors to the A.P.S is only coming up at between 2 and 4 volts!!!

Is that the voltage on each side or is that because you are measuring two points carrying mains voltage together?

 

[anton07]

The fan does go up to full speed.I phoned up Glowworm and the guy said to check the continuity across the A.P.S first,then the low water pressure switch then the high limit stat as the three run in series.However there is no continuity across the A.P.S,continuity across the low water pressure switch and no continuity across the high limit stat so I am completly bamboozled!!!

 

[Soggy_weetabix]

Tony has the answer.

A good boiler woth holding on to as its not made by baxi/potterton.

David

 

[tabs]

Try taking the stats on the flow and return out and cleaning them up with a bit of sandpaper. U could also test them with a meter but sometimes they will look ok but not work if they are not cleaned.

 

[Agile]

"""no continuity across the high limit stat so I am completely bamboozled"""

It sounds as if the high limit stat is faulty then!!!

Its blindingly obvious to me so I am surprised that you are completely bamboozled!

Tony

 

[Paul Barker]

Could be just not making good contact with meter. Needs proving properly by bridging it out momentarily (NEVER PERMANENTLY).

However from the story so far the fan is coming on and the pump is running. There is no pump proving on this boiler, so simultaneously a voltage should go to the gas valve main solenoid. According to the MI's one leed is orange other is purple 24v transformer powers it, and presumably some rectification on the pcb so you are looking for 30v dc or so at the gas valve solenoid or at the relevent connector on the pcb. Not numbered on the MI's I'm afraid, but shouldn't be hard to trace. If you are getting voltage to the gas valve and the pilot is lit and no ignition the gas valve is either stuck, there is an interruption to the gas supply or the solenoid is u/s.

 

[tabs]

There should be a label stuck on top of the pcb box on this model showing the pcb numbered and labelled. I had this problem on the same boiler a few months ago. I far as I remember I think it was around 20v to the gas valve solenoid. I have the manual somewhere so I look it up

 

[Agile]

[quote="Agile
It sounds as if the high limit stat is faulty then!!!
Tony[/quote]

Having said that, I thought this stat was in series with the thermocouple and is it really was o/c then the pilot would be off.

OR

The stat connections have been removed from the gas valve and bypassed like one I saw last wek!

Tony

 

[Paul Barker]

There's a high limit stat in series with the aps and an overheat stat in series with the tc.

 

[anton07]

Im just finding it strange how there can be continuity across the low water pressure switch and none across the A.P.S or high limit stat as they are wired in series.The guy from glow worm now reckons both the A.P.S and the high limit stat could be faulty.I didnt think there would be continuity across the low water pressure switch if the A.P.S had to be closed though,which it is not!