Baxi Solo 3 40 PF boiler ? ?

[ben]

Hi -

I am renting a flat with a mate and it has the above boiler in one cupboard and a big tank in another.

Now I am worried it is using a lot of gas, it fires up regularly even when no hot water is being used. We don't use the heating any more so its just for hot water. The heating thermostat is turned right down.

On the big tank is a timer system which was on "On" before, but I have switched it to "Timed" , however even though the timer was not On the boiler was stiill firing up.

Also there is a dial on the front which I assume is a temperature dial for the hot water. Is it best to keep this low or is it more efficient to have it full turned round ???

Any tips appreciated as the gas bill for 2 months was over =A370

Thanks,Ben

[Roger Mills]

Would you care to upload some photos of the relevant bits (timers, stats, motorised valves, etc) somewhere - and post a link here - so that we can get a better clue as to how the system is configured? Do the radiators ever get warm, even though the heating stat is turned down?

Is there any possibility that the boiler could be used for things beyond your flat - such as heating other flat(s) in the same building? Have you verified that the gas bill is correct in terms of meter readings, appropriate tariff, etc.?

[ben]

Hi Roger I have uploaded photos to

are rather big sorry if loading times are slow the boiler has just fired up again even though I have not touched hot water all day and the timer is set to Off. I am worried what you suggested about a neighbour using the same supply is true, but I thought renting a flat we would have been told that, and how would bills be worked out ? I have decided to switch the boilder to the * position just before off so that it should fire up at all until I turn it up (I'm guessing?) Any help appreciated, hope the pics load ok and are of some use Thanks Ben

[ben]

to answer your other question - i havent noticed the radiators being warm - i dont think the heating is coming on unless we turn up the room stat..

[Tournifreak]

This is the same boiler as I have (I have the 60FP). I think it has an anti-freezing function, so that it turns on periodically in very cold weather to prevent pipes from freezing. I guess the thermostat that activates that function could be shot??? Jon.

[Roger Mills]

Blimey - you've got enough pipes, pumps and valves there for a small nuclear power station!

The labels seem to indicate that it's a mains-pressure unvented hot water system. My guess is that it's also some sort of heat bank - where a tank of hot water is constantly maintained, with the DHW and CH being supplied from it via heat exchangers. There are certainly at least two pumps - presumably one for circulating water between the boiler and tank and the other for pumping secondary water round the radiators. Judging by the cables at the bottom, there are presumably also some electric immersion heaters - providing an alternative source of energy input.

Again, according to the labels, the timer only seems to be for the CH - the primary circuit is intended to run as needed on a 7 x 24 basis - which is probably why the boiler fires up when you don't expect it to. You may not be

*using* any hot water, but if the water in the tank cools below its stat setting the boiler will come on to heat it up again.

Such a system *can* be very efficient provided the tank is *very* well lagged. It's difficult to tell from the photos whether yours has any lagging - if so, it would have to be inside the outer skin.

Maybe others will recognise the actual system you have, and shed a bit more light on exactly how it's supposed to work.

[Roger Mills]

I've since found this

which may be of interest - particularly the paragraph which says: "I most commonly repair PulsaCoil 2000s and PulsaCoil IIIs, but I am familiar with other Gledhill thermal stores too, including the BoilerMate, the ElectraMate, the systeMate, the GulfStream and the (long obsolete) Cormorant."

Note the "long obsolete" bit! It's pretty obvious from the pictures that the cylinder and pipework is a *lot* older than the boiler - the latter presumably being a relatively recent replacement. If you're renting for anything other than a very short period it would be worth trying to persuade (force?) the landlord to replace the lot with something more modern and efficient.

[Roger Mills]

I wondered at first whether it was coming on due to a frost stat - but am pretty sure that it's just the stat for topping up the thermal store which is activating the boiler.

[ben]

Thanks for the replies, so if the timer function is just the central heating then I can leave that permanently off?

You're probably right that it is just topping itself up when it goes below a certain temperature. Is there a way to make this process more efficient? Is it better to have the dial on the Baxi turned up higher so the water is hotter and it wont have to top up as regularly?

We have put the heating on a few times through the winter as some days has been sub zero temperatures, but its not been on a lot, and hasnt been on at all for about 2 weeks. I was just surprised at the bill.... We mostly just have showers and very few baths as well.

Will be moving out in May, so not worth chasing the landlord. However next property is going to have to appear a lot more efficient than this one. Can anyone advise on what kind of system I should look for? I do own a flat and recently had a Combi boiler fitted I was told they are pretty efficient, heating on demand... not constantly topping up when you aren't even using water?

[Roger Mills]

Yes.

The boiler temperature needs to be *high*. If the water coming out of the boiler is cooler than the stat setting on the tank, the boiler will cycle constantly on its own stat but will never meet the tank's demanded temperature. The system works most efficiently when the boiler runs continuously until the water in the tank is hot, and then goes off for a long time.

Carefully read the user instructions printed on the side of the tank, and do what they say!

[ben]

ok - i have switched the timer to off, and turned the boiler to full

as you mentioned it advises to do this on the big sticker on the tank

i will see how it goes.... thanks for your help!