Boulter Buderus boiler - what's it doing?

[xanderma]

We had a Boulter Buderus 500-24/S boiler installed in the summer. It seems to work OK, but it does a couple of strange things.

At times when there is nothing (i.e. hot water and heating) switched on, it still fires up for about 45 seconds, the digital display rises rapidly to about 65 degrees (although our maximum temps are set to 60 for water and rads) and then it goes off.

Also, again when nothing is switched on, it still makes a sound as if it is fired up, although I know it isn't as I've checked the gas meter and nothing's moving! It does have an electrical supply, so it must be doing something with that, I suppose, but what? I'm worried I'm wasting energy somewhere here.

Please don't ask me to call back the plumber - he was worse than useless, literally scratching his head at times! (Don't worry, we haven't paid him yet, he hasn't worked out how to submit an acceptable invoice!)

Also, I've just had the system serviced by British Gas, and the engineer had never seen one of these boilers before, so he couldn't answer my questions either!

[oldwoman]

We have a Baxi and it was doing this due to the pre heat switch. It came on every hour for about the same time as yours. It is keeping the water ready for you to use. It got on my nerves and I got it switched off. You will have this somewhere also.

[pilotlight]

xanderma,
Oldwoman's answer could possibly be correct, but as the boiler model number has a "S" at the end, I suspect it will be a system boiler ( not a combi - which indeed do have a pre heat facility ).
A possible cause of the first problem could be that the in-built frost protection thermostat has not been set correctly, especially If the boiler is firing up when the external temperature drops. If this is the cause of the problem, a boiler engineer would be required. Contact the manufacturers ( details will be in your users handbook ). You should have a manufacturers 2 year guarantee.
The second problem is probably not a problem at all, as the boiler will probably have an inbuilt facility to ensure that the pump does not "cease-up" -- it brings the pump into operation every so-often.
Hope this helps.

[oldwoman]

Http://www.boulterbuderus.co.uk/ Click on Technology,then DBA I think this is what yours is doing the same as mine.

[gasman]

I am not suprised a British Gas engineer has not heard of these boilers. Before i started my own business and worked for Britsh Gas the only boiler in there eyes is a worcestor bosch boiler. any other make is like a bad smell to them, lol.
Infact Buderus are Europe's largest manufacturer of high efficiency condensing boilers and have over 275 years of experience and expertise in the European heating industry. and have recently started up in the UK now. But i am digressing here so on to your question.
I would not worry at all about it randomly firing up as oldwoman says it is preheating, and in doing this it is infact been more efficient and saving you money.
And it will also once every 24hrs (at random times) run the pump and fan for a short time to stop them from seizing up and keeping everything in tip top condition. You will also find in the winter it will actualy activate the heating for a short while even when the heating is switched off. ( If it has not been used and the temp drops below 4 degrees). to stop the system from freezing up. These are very intelegent boilers.

[xanderma]

Thanks you everyone for taking the trouble to reply.

gasman, you're a true star - given the incompetence of our plumber, you'll understand why I was worried! But you've put my mind at rest nicely. You don't happen to work anywhere near East Yorkshire do you?!

[xanderma]

oldwoman - I've just had a look at the website you suggested - I looked there before but didn't think to click on the 'technology' bit! I'm a bit chuffed with my little self actually, cos I thought it was behaving as if there was a reservoir somewhere and this confirms my suspicions! BTW, I specifically asked out BG engineer if there was one, and he said no!?!