No hot water - Glow-worm Ultracom 30

[Tom JE]

Hi Chaps,

I've had my Glow-worm Ultracom 30 cxi combi boiler fitted for 18 months now. Strange things have been happening over the last two weeks.
During the night, the boiler would always seem to be doing 'something' regardless of whether the heating was off or hot water not being supplied. After checking the status codes, it seemed that the boiler would go through the cycle of supplying hot water, obviously without actually supplying any (no taps on etc). I assumed that I'd had a leak so closed the isolation valve supplying mains water to the boiler - it still went through this cycle continuously. Each cycle would only last about 15 seconds, as soon as the boiler ignited it immediately shut down again and onto the post fan sequence.
Last week however, I noticed that the boiler only supplied hot water for 30 seconds before running cold. This weekend I have been unable to get any hot water from the boiler at all. The status code doesn't register any demand for hot water when any of the hot taps in the house are turned on.

From what I understand, the boiler is still under a 'parts only' guarantee but I'd need to pay labour costs. Before I go down this route, are there any simple fault finding steps I can take to eliminate something stupid I may have missed?

I've read online about problematic flow sensors - could this be the cause here?

Thanks in advance,

Tom

 

[Piers1989]

Hi Tom

When you were looking at the status with the hot water issue was it S.14 or S.24?
S14 is hot water demand (actual flow through the appliance)
S24 is preheat

I presume you are familiar with the diagnostic menu (status is D99), have a look at D36 when the hot tap is on. The D36 is the flow rate in litres per minute. This will tell you if the boiler is seeing the flow. Its quite possibly the flow sensor that's the problem and this will be the cause of it not seeing the demand and changing to the correct status.

Further testing would be required at this point so its best to get someone in to have a look at it.

I hope this helps

Piers