Worcester Bosch CDi combi boiler - huge gas usage

[leonine98]

Hello, we bought a new house a year ago and it is using about £80 of gas per week at the moment - around 150 units per week for a 4 bedroom house with 2 bathrooms. We run heat for 2 hours in the morning at 20 degrees and 6 hours at night and heat water for around 5 hours morning and evening combined. Combi has a megaflow attached and house has 2 heating zones but even if I only switch one zone on the usage is astronomical. I am living in a cold house too afraid to turn on both heating zones due to cost. We are very alarmed at the cost but don't know what to do as visiting heating engineers just quotes to install a new system for £6000 plus. Our metre has been checked and it is not faulty. Are there any possible reasons for this usage which we could fix rather than have to install a whole new system?

Any help greatly appreciated. Thank you.

 

[Deleted member 105431]

get your boiler serviced by worcester, make sure they gas rate and check it with a fga. Get your loft and cavity wall insulation checked and topped up, fit draught excluders and consider getting weather compensation intelligent controls fitted to the boiler. Check for a gas leak.

 

[ChrisR]

Everyone's idea of "warm" is different.
I've been in many houses where the bills seem high, and I've found them all uncomfortably warm.
All you can do is insulate - your bodies or your house.
CHanging the boiler/system will not make much difference, unless something's badly wrong.

 

[simond]

Hello there

A combi with a Megaflo attached? That is a strange set up.

To use £340 a month on a 4 bed house is quite impressive. So far every customer of ours who has complained of excessive gas usage has had a billing problem.

As it is only 26 Oct I can't understand how you know exactly what your winter consumption is already. Most of us are billed quarterly, unless you are on a smartcard prepay tariff.

 

[petit_pablo]

Heating a 4 bed house to 20deg for 8 hours will use alot of gas, perhaps not as much as you are using but still alot.

How much hot water is used? Baths showers etc? Does it need to be on for 5 hours a day?

I have a 3 bed semi and the heating is set at 17deg, 1 hour in morning and 3 in evening. The house is fully insulated and the temp doesnt really drop below 17deg so heat hardly ever comes on.

Just turning down the room stat 1 deg will save a few quid on those bills

 

[Agile]

Hello, we bought a new house a year ago and it is using about £80 of gas per week at the moment - around 150 units per week for a 4 bedroom house with 2 bathrooms.

Any help greatly appreciated. Thank you.

Something odd here!

A Unit is a kWh and that costs about 5 p for gas ! That would be about £8 per week! But thats too low.

Your annual gas bill should be about £1300 with average useage!

If you call round sharks to come free then they are not interested in your bills just lining their pockets by over priced quotations.

If you take them for a ride then they are going to be doing the same to you!

We dont go anywhere free, but we do give the best possible advice when we do go.

Tony

 

[leonine98]

Thank you all for your comments. The house has had its cavity walls filled and the loft is fully insulated. I an currently draft proofing everywhere. Worcester Bosch did a full boiler service immediately after we bought house and raised no issues. Would they have checked to ensure it was using the correct amount of gas? 100/150 units of gas per week is the metre reading, This is then converted to Kwh which comes to around £80 per week. We know, because we keep getting the bills.

I have offered to pay 2 heating engineers to do tests on the system to help me establish the source of the problem but they just look at the system and quote for a new boiler. The existing one is 8 years old. In both cases, when I don't accept the quote they have charged me for their visit and I am still none the wiser to the source of the problem. So, hopefully, you will accept I am not ripping anyone off. The house feels cold most of the time and the family complain they are not really warm so I feel I need to understand what is happening. We have never had this problem with other properties and love visiting our friends in the evening as their houses are so much warmer. Any more ideas gratefully accepted. Thank you.

 

[tonybhoy]

Gas usage seems excessive. How do you use your heating?

For example, I have had two customers in the past month complaining about excessive gas bills however under interrogation both of them had turned the boiler stat down to about number 1 and all of the TRVs down to 2 or less.

Result boiler cycling like mad and in one case nearly boiling hot water house freezing and gas bills astronomical.

My advice to them was to turn up boiler stat to max , open up TRVs and reprogramme the time-clock to less on times which will result in hotter house and less boiler cycling and less gas usage. At the very least those two customers will get value for money in terms of warmer house for the money they are spending.

 

[Agile]

Its not possible for a boiler to use much more than its rated gas consumption otherwise it would overheat and burn out. In any case that would provide more heat to the house.

Its easy for you to check the gas consumption yourself. Search on this site for "gas rating".

Otherwise, tell us what model of gas meter you have and give us the two readings 24 hrs apart.

Tony

 

[SteveZodiac]

My advice to them was to turn up boiler stat to max , open up TRVs and reprogramme the time-clock to less on times which will result in hotter house and less boiler cycling and less gas usage.

Very interested in your comments tonybhoy as I have an 8 year old WB 28CDi which I've always suspected has been more expensive to run than it should be. By boiler cycling I guess you mean that it's constantly stopping and starting over long periods which uses a lot of gas. Can I ask a few questions?

1. Are you saying it's better to have the boiler AND trvs set to max, or should the trvs be set for the temperature you want?

2. If you should set the trvs for the temp you want (less than max), won't the boiler cycle anyway?

3. By less on times do you mean have everything set to max but instead of having the heating on for, say, 5 hours continuously in the evening have it on for 3 separate periods of, say, one hour with gaps in between?

4. Would a room thermostat help at all? (I only have trvs).

We keep being told that if we turn the heating down by even 1 degree we'll save money, but from what you say it's not quite as simple as that.

 

[JohnD]

Are you reading Cubic Metres off your meter, and when you say "Units" do you mean Cu m?

Or is it old old Cubic Feet one?

Who is your gas supplier?

Have you got women in your house who like to turn the heating up and leave all the doors open? Including internal doors?

Have you got a swimming pool?

OOI I used 1300 Cubic metres of gas in the last 12 months which cost about £720

When you look at your old gas bills, how many cubic metres did you use in 12 months?

 

[tonybhoy]

My advice to them was to turn up boiler stat to max , open up TRVs and reprogramme the time-clock to less on times which will result in hotter house and less boiler cycling and less gas usage.

Very interested in your comments tonybhoy as I have an 8 year old WB 28CDi which I've always suspected has been more expensive to run than it should be. By boiler cycling I guess you mean that it's constantly stopping and starting over long periods which uses a lot of gas. Can I ask a few questions?

1. Are you saying it's better to have the boiler AND trvs set to max, or should the trvs be set for the temperature you want?

2. If you should set the trvs for the temp you want (less than max), won't the boiler cycle anyway?

3. By less on times do you mean have everything set to max but instead of having the heating on for, say, 5 hours continuously in the evening have it on for 3 separate periods of, say, one hour with gaps in between?

4. Would a room thermostat help at all? (I only have trvs).

We keep being told that if we turn the heating down by even 1 degree we'll save money, but from what you say it's not quite as simple as that.

Boiler stat should be turned up to max for central heating and a room stat is essential. Basically your aim is to get as much heat into the house as quickly as possible then have the boiler off as long as possible.

Trvs exacerbate cycling of the boiler gas valve particularly on a combi by ensuring the return temp back to the boiler is high ,that is if you use them they way they should be used of course if however you leave them on max like most people then of course the rads will always be calling for heat and the boiler won't cycle as much but you will more than likely on most days be wasting fuel by overheating your house.

Bottom line in saving money/fuel is to ensure the boiler is off and is only on when it needs to be.

A combi system fitted only with TRVs and on a programme of ,say,five hours a night will try to constantly heat the house even if the TRVs are closed and some/most rooms are up to temp.

TRVs cannot turn off the boiler only a roomstat/programmable roomstat can do that.

A decent programmable roomstat (Honeywell CM927 @ approx £100) will pay for itself in a year.

Insulation is probably just as important though,however a well insulated house with no roomstat will ensure that the boiler cycles even more than an uninsulated house


Tony.

 

[SteveZodiac]

Boiler stat should be turned up to max for central heating and a room stat is essential. Basically your aim is to get as much heat into the house as quickly as possible then have the boiler off as long as possible.


A combi system fitted only with TRVs and on a programme of ,say,five hours a night will try to constantly heat the house even if the TRVs are closed and some/most rooms are up to temp.


TRVs cannot turn off the boiler only a roomstat/programmable roomstat can do that.

Tony.

Great stuff, thanks Tony. I've often wondered why my installer didn't fit a room thermostat (in 1994) and assumed that the boiler is cleverer than it actually is. I wonder if British Gas still get mocked for insisting on a room thermostat on their installations! Obviously if the timer has switched the boiler on it stays on cycling until switched off, and the TRVs are almost irrelavent. Looks like a simple setup would be to fit a room thermostat in the room you want kept warmest with TRVs everywhere else set the way you want. Exactly what I had in my first house 27 years ago! Blindingly obvious really.

Steve

 

[Agile]

I wonder if British Gas still get mocked for insisting on a room thermostat on their installations!
Steve

I dont know what makes you say that!

The regulations require a room stat and TRVs!

British Gas and all compliant installers fit them because they have to do so and they save energy if they are used correctly.

Even having the equipment does not mean that many people are going to use them.

Tenants for example set everything to max and open windows if it gets too hot!

Tony

 

[Corgigrouch]

Customers still look at me as though I was an alien when I mention expensive nonsense such as room 'stats and TRVs... Clearly, for some, the price of gas is not high enough yet.

Even had one mad muppet call me a crook, trying to rip him off when I told him that a room 'stat was mandatory...