New boiler costing more

rl1

We had a very old boiler and were constantly been told everyone time it was serviced that we needed a new one and it would saved money. We decided we would have a condensing combi boiler and had a new one installed. Unfortunately rather than saving us money it is using more than twice the amount of gas as the old system. We have had the boiler serviced and the meter tested and so far no one can come up with an explanation as to why this should be happening. Can anyone help?

Pssst

Did your old boiler have a hot water storage cylinder linked to it? What size house do you live in/how many people/how many showers/bathrooms etc?

rl1

Yes it was a boiler and a hot water tank. There are two of us, one shower, no bath.

swiftnick

Crikey!

Can't offer a solution but when we had our 25 year old gas boiler replaced with a condesing boiler our bills were almost halved.

Nick

Robbo77

I would recommend getting the boiler manufacturers to carry out a performance check on the boiler. The combustion settings and gas/air ratio must be a mile off before your gas consumption is that high. Either that or there is a component fault with the boiler causing it to operate continuously. Hope you manage to get this sorted.

Possetjohn

Hi rt1

I am really surprised. We had our 25 year old wall hung boiler with cast iron HE (55% efficiency on a good day) replaced by a Valliant Combi at the beginning of November. Our gas consumption has dropped 15% in a similar period to last year, despite the weather being much colder. Radiators are hot much more quickly (15mins rather than 30-45 mins) and the house is warmer.

Condensing boilers are usually around 90% efficient compared with older cast iron HE boilers being 50-60% efficient. If you are burning extra gas the heat must be going somewhere!! If you are burning twice as much gas that is approximately 3x more heat!!

I cannot see any way that should be happening, but some suggestions below.

How are you comparing consumptions? (time periods etc) This winter has been much colder!
The boiler is operating properly in condensing mode? (white steam plume from boiler exhaust)
Are you using the heating in the same way as before?
Did you have a new roomstat fitted? If it was the programmable RF type, is the daytime and overnight temperature set correctly. (By this, I mean can the heating be coming on when you are out of the house or asleep? Assuming you are!)
Is the instantaneous hot water mode set? (this causes the boiler to fire to keep the direct hot water HE preheated. Wastes gas IMO though not this much!


Robbo77's suggestion is good especially if the boiler is still in Warranty!:T

brig001

Is the shower fed from the hot water? If so, you could be getting more hot water out of it than before. In fact, you could be using more hot water generally since the pressure will be higher. If you are looking at the past three months or so, don't forget that it has been colder than last winter.

robv_3

Silly question, are you comparing with figures a year ago?

Eg, you gas consumption will be higher in December than November and Gas prices have gone up 30+ percent since last year.

rl1

Thanks to everyone for the responses and suggestions. It is a bit complicated but I am comparing the usage to two years ago because for the whole of last winter we were out of the house due to flooding. We had just had the boiler replaced when this happened so never had a chance to test it out properly before it ran out of warranty.

We have had the meter tested by British Gas who we have our maintenance contract with but am currently awaiting our gas suppliers to carry out tests once we have given them day by day readings. Even they think the readings are unrealistically high.

Will let you all know the outcome.

danhar707

I'd like to hear the outcome too. Got a similar problem. £500 gas bill for the winter quater! The combi boiler seems to be emitting a lot of fairly-warm steam from the flue too. Can this be normal?

27col

Surely, what you should be doing is to compare the amount of gas used, not the cost. As has been said, the prices have varied considerably over the last couple of years. The variations would make it difficult to compare like with like.
As to the the steam from the flue, I think that you will find that this is normal. Something to do with the lower temperature of the flue gases and condensation. I hope that eliteheat or someone else more knowledgeable than I will confirm this.