How exactly does a gas boiler work?

HappyMJ

ally18 wrote: »

Riverstyx,

Thank you so much for your replies, I'm sorry I didn't have chance to read them until this morning.

I have read something about the eco-mode function but it wasn't clear that that was what it was for. I'm not in during the day so it would be best for this to be turned off. I will have a look at it tonight when I get home.

Again, many thanks for the explanation. It is much clearer now.

There are disadvantages in turning it off...You will use a lot (in my opinion) more water running the tap longer waiting for hot water to come through. Depending on the cost of water in your region it's usually cheaper to have the water preheated even though it uses gas for 5-10 seconds many times per day.

If you are not on a meter and additional water costs you nothing then turn it off....or if you save the cold water that would have otherwise gone to waste and make sure you use it then it won't cost any extra.

espresso

The 55 and 75 degree boiler settings are the manufacturers default settings.

You should switch off DHW preheat (Eco-mode) and then investigate why it is taking "about 2 hours" to raise the temperature from 16 to 18.5 degrees when it is not even winter yet!

ally18

espresso wrote: »

The 55 and 75 degree boiler settings are the manufacturers default settings.

You should switch off DHW preheat (Eco-mode) and then investigate why it is taking "about 2 hours" to raise the temperature from 16 to 18.5 degrees when it is not even winter yet!

How long exactly would you say it should take? As I say, this is all new to me as I've been used to an old system which took ages and then never got above 13degrees.

Thanks

HappyMJ

ally18 wrote: »

How long exactly would you say it should take? As I say, this is all new to me as I've been used to an old system which took ages and then never got above 13degrees.

Thanks

Half an hour..unless you have the window open.

ally18

HappyMJ wrote: »

Half an hour..unless you have the window open.

Half an hour, really!?

I wonder why it took mine so long then? Hmm

The thermostat has been placed in the hall, not in line with the front door so that opening and closing shouldn't make a difference should it. I don't feel any draughts coming through either.

It isn't a really large hall but the stairs obviously are there to the landing and then a third set of stairs to the attic. I wonder if this being a large area, it could be the issue. Plus, on the day in question though, I did keep opening the internal door from the dining room because I wanted to keep checking the stat.

The front room has never, ever been above 13 degrees in all the 10 + years I have lived there but on that day, it was absolutely lovely.

I think next time I need to switch the heating on, I will leave it alone, keep all doors closed and see how long it takes then.

Thank you all for your replies.

Ben84

I assume it's a modulating boiler, which is different to the old ones.

Old boilers have a fixed output gas burner, which burns the same amount of gas per minute whenever it's on. For it to heat your house during times of lower demand, it simply switches on and off to control the heat output by time. As an example, a 20kW boiler that only needs to produce 10kW over an hour will turn on and off multiple times, which if you counted them would add up to 30 minutes on and 30 minutes off.

Meanwhile, a modulating boiler will come on full until the house is heated, then it turns down the rate of gas burning to try and match the output to the heat demand. It may occasionally shut off if the minimum setting is still too much, but for a lot of the time it will run constantly with a low flame. They also tend to be quieter and more efficient than old boilers like mine which ignite with a big clank and whoosh and rumbling over and over again, which isn't great in the middle of the night. Anyway, although it can be worrying that it's humming away burning gas all the time, it should still be using less. It's certainly not flaring gas at the rate old ones do every time they're lit, and the benefit is that with a smaller flame, the heat exchanger and radiators are comparatively oversized and transfer heat more efficiently.

ally18

I had a look at the booklet for the QSense stat last night but unfortunately it is just basic and doesn't describe how to turn it on to eco-mode so will have to download the full instructions.

Thanks again for all the advice, I understand the workings of the boiler much better now.

southcoastrgi

you should have the user guide for the room stat & installation & servicing book for the boiler, if you don't the installer has taken them & you need to speak to him & get them back, btw if you are searching it's now called the Baxi Avanta not Remeha

ally18

A quick update, I have had the heating on again and it is still taking around two hours to increase two degrees.

I am obviously heating all the air in the hall, landing and attic which is why it is taking so long to get to temp so do you think I should have the thermostat moved from where it is?

If I have it put say in the living room I shouldn't be wasting all that heat should I?

Thanks for any advice you have.

Fruit_and_Nut_Case

Nobody has asked yet, but do you have Thermostatic Radiator Valves (TRVs) fitted in any rooms? They will significantly affect the way your heating works.