Boiler keeps trying to come on with no demand, any ideas?

[Madmog]

Over the last 24 hours our combi boiler (Worcester Bosch si25 I think) keeps trying to kick in, either cycling (as it does if not used for 24 hours) or coming on for 30 seconds and shutting down. We've got it on timed set at 15c as we don't need the heating on at the moment, but it's trying to come on a different times and doesn't relate at all to the timings. Have put a thermometer in the room where the thermostat is and it says it's 19c. It's working as we'd expect on hot water and pressure is normal.

Does anyone have any ideas what could be wrong?

We're going to see what happens over the next few days and then I suspect we'll want the heating on as it gets colder, so will see what happens then.

It might be a combi with a keep-hot function to reduce the delay in hot water coming through the taps. Look for an eco setting to turn it off. If you have lost the Owners Manual download it from the makers website.

I am assuming that none of the radiators are getting warm.

Thanks for your reply. It's an 28i Junior Worcester Bosch and doesn't appear to have a keep hot setting for the water. There is an eco setting for something, but this isn't on. We've had the boiler running for three showers and general washing and haven't had a problem with that.
It just keeps trying to cycle, sometimes igniting for approx. 30 seconds. None of the pipes leaving the boiler are getting hot when it does this. We've got it set on timed at the moment at 15c, so shouldn't be trying to come on. In any event it's trying all times of the day.

Turn eco on.

I mean, the eco will turn off the keep-hot (if present).

I mean,

Eco on = keep-hot off.

I haven't noticed the boiler coming on before and we've not made any changes to the system, but have only lived here for three months, so it's trying. Perhaps, somehow it's come off eco. Anyway, will go and put the eco button on and see what happens. Thank you!

It's part of its cleaning/maintenance cycle.

Don't worry.

We just had one fitted this week and had the talk through and he said don't worry if it fires up for no apparent reason.

You can make it stop I think but can't remember how. Otherwise just let it get on with it.

(worcester 30 here)

Well I mean I think that might be it. I haven't used ours yet so not 100% sure.

Ring someone and check though - who fitted it? Is it still under warranty? Or ring Worcester if they have a technical number.

www.worcester-bosch.co.uk/cache/file/620/greenstar-gas-boilers-brochure.pdf

page 11

"ECO mode – When set to ECO mode, the CDi Compact will use less gas or LPG, as the energy will only be used on demand, allowing for energy-saving fuel consumption.

Comfort mode – All Greenstar combi boilers have an in-built ‘keep hot or pre-heat’"

Asked my oh he's a gas engineer he asks which room the boiler is fitted?

PigletJohn, just to let you know the boiler has stopped igniting since putting it on Eco. I'm still not sure why it suddenly started doing this though, but hopefully this was the problem. Thank you. Fingers crossed nothing is greatly wrong with it, and the heating will kick in as it gets colder next week!!

Assuming this was the problem and for those who do want to use the keep hot function, it doubled our gas use for the time it was on, admittedly only for hot water and cooking but makes you wonder if it's worth it.

Soonish, our old Worcester Bosch and this present one during the time we've been in the property have never fired up like this, so if your new one does, do check if it's on eco as it does seem to use the gas.

Wishfulmakeupping, hopefully problems is solved now, but the boiler is on the outside wall in the kitchen if this has any relevance.