Which is the more efficient?

[Harry Bloomfield]

Condensing boiler heating the entire house, or that plus a normal radiant gas fire in use in the living room, just to increase the living room temperature.

We normally just have the CH on alone set for 21C - I 'm just wondering if it might be worth running the gas fire on the colder nights. A gas fire has been there (not the same one) and completely unused for 35 years. Interior doors are normally left open, the stat is in the hall, close to the living room door. The house is very well insulated and even with sub-0C outside, the indoor temperature never fell below 17C with no heat input over during 10 hours night.

The radiant gas fire has only served so far as a back up for brief heating system failures.

[Roger Mills]

A gas fire might provide a nice focus, and a bit of extra heat on the occasional winter evening. But I wouldn't use one as part of my regular heating strategy - they're hideously inefficient compared with a modern boiler. If the room isn't warm enough, install a larger (or additional) radiator.

[ss]

We use a wireless thermostat and just take it in to whatever room we are using, normally the kitchen or the lounge. The only downside so far (as I generally let the wife have the controlling element) is if she is doing a lot of cooking then I shift the thermo in to my study as the temp in the kitchen is higher than the kick in temp of the thermo.

[Fredxxx]

You can have more than one, and wire the receiver relay contacts together.

That way one hot room won't override the demand for heat for another room.

[RJH]

80% efficient isn't unusual, not far behind the very best condensing boilers . . .

[harry]

The snag with a gas fire is it draws (cold) combustion air into the house, so partially defeating it's purpose.

I would turn radiators down/off if you want to economise.

[Bertie Doe]

Shouldn't the cold air go back up the flue? I thought gas boilers were hermetically sealed?

[Chris J Dixon]

With a glass-fronted appliance the air movement is quite small, and the heat considerable, even at a low setting.

I'm not counting meter flashes to compare, so it will have to wait for smart meters to decide it.

On the other hand, many years ago, at another's insistence (against my strong advice) I had an open hearth coal-effect gas fire fitted, and I'm convinced that the net effect was to cool the room. I was glad to leave it behind.

Chris

[Harry Bloomfield]

I'm not too bothered about absolute economy, we are already quite economical. We burn slightly more than 50% of the gas that a comparable home uses and that includes double oven and hob, CH & HW on all day. It is just set back to 16C overnight, during which time the boiler never needs to fire.

I was more interested in not making the economy worse, by using a gas fire.

[News]

In message , Chris J Dixon writes

Agreed! We inherited one when we moved here. Quite pretty, I suppose, but heating was one objective it did not meet. We ripped it out and replaced with a proper open fire.

[Roger Mills]

The OP was talking about an *old* gas fire. I have a Cannon Caress coal-effect fire which is about 25 years old. It was efficient for its day because it has a separate heat exchanger through which room air circulates whilst being heated by the flue gasses. Even so, I can't find any published efficiency figures[1] for it - but I would be amazed if it were anything like 80%. We use it very occasionally for a bit of top-up heat in the winter, and sometime on a cool summer evening when we don't want to put the main heating system on.

[1] The user manual lists the heat input (7kW, 4.13kW and 2.78kW) for each of its 3 settings, but nowhere does it say how much useful heat gets into the room! Its GCN is 3213281 in case anyone has a spec. for it.

[charles]

Some gas boilers are "room sealed" gertting their fresh air diretly form outside. Others , like ours, draw the air from the room in which they are installed.

[Dave Plowman (News)]

I'd guess there aren't many non RS boilers still in use. My previous one, installed in the '70s, was RS.

The big problem with a non RS type is it can allow carbon monoxide into the room if faulty. That's usually how people get killed by a faulty boiler.

[Harry Bloomfield]

Roger Mills formulated on Wednesday :

I can't actually see a name on it without pulling it apart, but...

It has three pots, completely open at the front just a chrome guard, no coal/ log effect. The control allows 1 lit, variable up to 3 lit. It has some sort of heat exchanger to warm the air, vented at the top and a flame failure device and piezo ignition.

Its predecessor was never used, but I replaced it for the above more modern unit, which likewise has never been used in earnest.

No extra heat is needed in the room, I just wondered if using it might produce more efficient heat than that of the main condensing boiler.

40 years ago, when we first moved in, there was no CH, just a single gas fire of the same style as the only form of heating. No insulation at all, single glazed, draughty windows and doors - it wasn't much warmer inside than out in winter.

[Chris French]

In message , "Dave Plowman (News)" writes

And the installation requirements mean that the room normally needs a permanent vent, and therefore a permanent cold draught. Could be a bit of a PITA in a regularly used room.

Fortunately our old open flued boiler is in the utility room out of the way.