Boiler fault; Glow worm Swiftflow 100e

[Shox Dr]

We've the above boiler, fitted around 15yrs ago.

Every so often (once a yr)it would stop producing Hot water, a simple press of the reset button cured it. But over time the frequency has increased.

It will not fire up at all, for either H/water or CH.

I've checked all the sensors etc. and found no faults.
The main board had blow components and dry joints and has been replaced, with a rework.
The same for the Temperature adjustment board. The Ignition unit/board has been replaced with new unit.

So you'd think it would run now. Oh no !!!

Powers up, and goes through a short check cycle. Reset light comes on for a fraction of a second.

Once finished any demand for water or CH; Boiler starts, fan runs, pump runs. then the reset light comes on.

Bar changing the gas side I'm at a loss as to what's wrong.

Suggestions please.

 

[Seadog]

It seems to indicate a problem with either the ignition or gas valve but do check the water pressure switch first. Can you see sparking at the electrodes through the combustion window once the pump has started? If you can see sparking the most likely fault is the gas valve. There's normally an audible click when this opens. If you have ignition and no audible click then measure the voltage at the gas valve solenoid (should be 240v ac). If there's nothing at the solenoid then you've a control board problem, if there is voltage then the solenoid would appear to be faulty.

Graham

 

[Shox Dr]

Thanks I'll check those.

And welcome to the forum.

 

[Shox Dr]

No spark, and No 240v at solenoid

 

[RonA]

We've the above boiler, fitted around 15yrs ago.

Every so often (once a yr)it would stop producing Hot water, a simple press of the reset button cured it. But over time the frequency has increased.

It will not fire up at all, for either H/water or CH.

I've checked all the sensors etc. and found no faults.
The main board had blow components and dry joints and has been replaced, with a rework.
The same for the Temperature adjustment board. The Ignition unit/board has been replaced with new unit.

So you'd think it would run now. Oh no !!!

Powers up, and goes through a short check cycle. Reset light comes on for a fraction of a second.

Once finished any demand for water or CH; Boiler starts, fan runs, pump runs. then the reset light comes on.

Bar changing the gas side I'm at a loss as to what's wrong.

Suggestions please.

The fan may be running but is it achieving the right pressure to operate the pressure switch. If the switch doesn't make nothing happens. My boiler admittedly not a Glow worm had similar problems only resolved by changing the fan. The fan bearings get a great deal of wear in the course of normal operation.
Have you or can you download the service manual most have a fault finding flow chart
RonA

 

[Shox Dr]

Hi Ron. Not sure if the fan is causing enough vac to trip the micro switch. I've linked it out and has made no difference, it won't fire up.

Out of curiosity, I'm off to do a pressure test on the fan. (back in five)

 

[Shox Dr]

great the ffin fan doesn't work now

 

[RonA]

great the ffin fan doesn't work now

I think you should obtain a copy of the fault finding chart, the you can eliminate one by one the interlocks which prevent the boiler kicking in. Interesting that the fan has stopped running though.
This might help http://letsfixit.co.uk/wp-content/uploads/SWIFT-FLOW-100E.pdf
RonA

 

[Shox Dr]

Sorry meant to say I've both Install and user manuals. So far I've

I had a mate rebuild the main board; No change.
I bought a new main board; still no luck.
Had same mate rebuild temp board; not luck
Just bought (NOS) Ignition board; still no luck.

 

[mart]

When I had a similar (maybe not the same) problem with an old Glow worm boiler it turned out to be the overheat cut-out device that needed replacing. On my boiler this device was a round black item about the size of a 1p coin and had two short wires coming from it.