GAS boiler - cheaper running costs?

alibopo

Hi,

I recently called the BRITISH GAS energy helpline and asked what was the best way to run a COMBI-BOILER. The advice AT THIS TIME OF YEAR (winter) was to turn the temperature of the water going to the radiators up to its MAXIMUM. I was surprised by this, as I understood the savings and efficiency from a condensing boiler came when the temperature of the water RETURNING from the radiators was at about 54-55 C. At maximum setting it is likely the return water temperature will be well above 54-55 C. Apparently this temperature is critical to allow CONDENSATION to take place and to allow the boiler to achieve its HIGHER EFFICIENCY. If the water returns at a higher temperature there is little or no condensation - which means the boiler behaves as a CONVENTIONAL boiler and the higher efficiency is lost. I wondered if this advice from BRITISH GAS had more to do with STOPPING the condensing, and reducing the number of frozen condensate pipes, rather than energy efficiency. Basically, I believe this advice means that at this time of year, when I am using the MOST gas, I will be using about 10-15% MORE gas because my boiler is not achieving its maximum efficiency. I wouldn't dare suggest that the ADDITIONAL REVENUE from customers SPENDING MORE on their heating was of some benefit to the gas supplier, but it did occur to me. I decided to see how my house felt running the boiler in proper HIGH-EFFICIENCY condensing mode. For about £1.50 from EBAY I bought a battery powered temperature gauge with a little remote sensor attached. I tied the sensor onto my boiler return flow pipe with a bit of string. I then spent a few days checking the return water temperature when the boiler was running. From slightly above a 3/4 setting (where the last British Gas service engineer left it) I progressively reduced the temperature day by day until the return water temperature dropped just below 55 C. The final setting was just below the 1/2 mark, which was quite surprising. Inside the house, the radiators still feel toasty and warm, and I haven't noticed the rooms achieve their set TRV temperatures any slower than before. I do have quite big radiators, but I'm in an old high-ceilinged Georgian property. I'll have to wait and see what my gas use is like to see whether I have made any SAVINGS, but if the people who DESIGN the boilers know more than those who SELL THE GAS to run them, I should see a noticeable drop in my gas consumption. Luckily my condensate pipe runs internally to join a waste pipe, so I don't have the problem of it freezing. Installers are now shifting to this system, using small pumps if necessary to move the condensate to a waste pipe internally. I think anyone stuck with an external condensate pipe should consider getting this as an upgrade to save them the risk of the pipe freezing. Has anyone else had experience or success with fine-tuning combi-boilers or any thoughts on my experience?

Cheers, alibopo.

C_Mababejive

I disagree with BGs advice.

The most efficient use of a gas boiler in order of effectiveness/least cost is..

1) OFF
2)At minimal pre programmed times and at the lowest roomstat/cylinderstat/TRV stat settings you can be comfortable with

I would never consider running a boiler at max stat setting regardless of whether it was conventional or condensing.

Keep it simple...Gas on>meter turns> ££££

oldskoo1

Of course it's cheaper to run it off but it's -6c outside!

My boiler is not a modern condensing modulating type boiler so right now it's on max. This is purely a thermostat so it just controls how quickly the boiler turns off. So set lower it doesn't reduce the gas coming into the boiler, it just turns off the boiler quicker leading to more cycling which is inefficient.

On modern, condensing boilers it will modulate the gas flame to keep it operating efficiently. It is just as important to ensure the radiators are balanced to ensure it can achieve the correct return temperature. If it senses the return is too warm it will reduce the gas flame down to as low as 30%.

In these cold temperatures you really should have it on near max, to raise the internal house temperature, you still need it to be about 20c right? Once it gets close it will begin to modulate the burner down anyway.

Sweey_as_a_nut

I had a new boiler put in a week before xmas, I wrote about it on here.
Yesterday before I put my heating on I took a reading and this morning I took a reading again and I found I had burnt 5 units. It was on until I switched it off at 11.00pm I had the temperature set at 18.5 at the highest temperature and 15.5 at the lowest, I had the temperature on the boiler set at 65deg. the amount that cost was £2.55. I am in my seventies and fit...so far. I do dress for it, and move about.

Ally74

I was under the impression that for more efficiency with a condensing boiler it's best to lower the flow temp. :- https://forums.moneysavingexpert.com/discussion/4205717

Setting number 2 on my boiler is quite capable of heating my home to the desired temperature with the boiler running for much longer periods.

C_Mababejive

#3 Indeed though my thought pattern is that for many of us,the days of cheap and indeed affordable energy is now over and so for most of us,the answer is use less.

Are you sure its -6 c? I only ask as at my location about 10 miles south of manchester i have measured an outside air temp of +8c and my current inside temp is a comfy 17c despite the fact that the heating switched off at 07.50 this morning and no further heat has been supplied.

ollski

You're aiming for a 20 degree difference between the flow and return pipes, without knowing if this is what you have no-one can tell you where to set the stat. Most condensing boilers will have a mark where your most efficient setting should be if your system is set up correctly.

unclebulgaria

One of the simplest things you can do to limit your gas usage is close your internal doors, especially if you have thermostatic radiator valves fitted to the radiators which wont switch off the flow to your radiators if they are heating every other room in the house by means of open doors.

Jonesy1972

We've tried everything suggested in this thread and elsewhere to reduce our gas consumption, then came accross a new valve that reduces the water and gas consumption of combi boiler or water heater called the Guardian Flowsave, they have a website that you can purchase directly from.

British Gas offer a similar product, but as you would expect is more expensive, I fitted this one myself and it was a doddle.

The estimated average saving is £150 per year, so it pays for itself in 3-4 months. We've had ours fitted for just over a month and it's working well so far............

Andy_WSM

Jonesy1972 wrote: »

The estimated average saving is £150 per year, so it pays for itself in 3-4 months.

How? I doubt most people spend £150 a year on hot water, let alone have the ability to "save" that much - and the valve has no bearing at all on the heating side of the system.

oldskoo1

You can tick off the checklist

comparison site with meter readings for the year

insulation in loft and walls, draft proofing, trvs

then you can tune the system a little

then you can set your timers conservatively

then you can turn down your hot water temperature to around 60c

after all of this your bills are what they are

your only other option is to turn the heating off.

Spending more money isn't the route to savings. Even on parts, gadgets, boilers. Unless yours is broken.