Worcester Bosch 28CDI large gas bills should i replace it?

[AdrianMealing]

Hi all,

had one of these for about 5 years, the only issue i have had was a diverter valve failure which was replaced about 2 years ago, regularly serviced, runs 8 rads and a towel rail, 2 thermostatic showers (not run at the same time), no cylinder. Also gas hob.

As the prices of gas have rocketed i have noticed a dramatic increase in my running costs, have used all the comparison sites to look at a better deal, but it appears i am on a good deal at the moment.

If i upgrade the boiler, to something newer how much of a saving can i expect, what do i need to look for in the specs that is likely to save me money, any thoughts appreciated.

 

[45yearsagasman]

Everybody has noticed an increase in running cost due to the price hikes.
What you need to calculate is your gas consumption.If that has suddenly shot up then that needs to be addressed.
Take into account that the Winter was fairly harsh and you would expect to use more gas.Start with checking loft and all insulation and bring up to current standards.Those things will save you more energy than replacing a perfectly good boiler,and will be kinder to your wallet.

 

[AdrianMealing]

Thanks for that, yes i know the winter was cold, could not get out of my street in a car for two weeks!!!

The house is a mid terraced Victorian property with a loft conversion, conversion was done about 5 years ago with approx 150ml Celotex + airgap used as insulation on the roof and 200ml rockwool in the floor, external walls are double skin brick, no cavity, windows are double glazed, about 10 years old, 24mm ish sealed units, not K glass.

Radiators are all convector type, with TRV (except towel rail)

My usage annually according to the info from my supplier is 2500 kWh at std rate, and 15269 kWh at discounted rate. Does that sound about right? ar is it high, i have no idea how to establish if i am using too much gas based on the above.

Maybe i just need to tell her ladyship to put on another jumper and leave the room stat alone.

 

[adlplumbing]

have full gas test done but boiler is very effceint a condeser would not save you much and think of ways to reduce heat loss check your rads top and bottom see getting hot equaly when warmed up but no boiler good boiler

 

[bengasman]

had one of these for about 5 years...
If i upgrade the boiler, to something newer how much of a saving can i expect...

If it is indeed 5 years old, it would be about as efficient as you can get. If it is 7 years or older, you could expect 5-10% reduction of your gasbill.

If you want to reduce your gasbill, the following points are the most cost efficient.

1. Turn the roomstat down; rule of thumb says every degree is 4%
2. Reduce the amount of hours the ch is on; 10% less time is about 10% less gas.
3. Reduce draft; doors, windows, open staircases and old chimneys create huge heatlosses.

 

[AdrianMealing]

Thanks adl, how do i go about getting a full gas test done, and what is involved, what will it tell me? and is it a gas company service, or can i get a local registered guy to do it.

As for the rads, yes they all get hot top and bottom, i have replaced a couple of rads when redoing rooms, in two cases i drained the whole system, so after refiling and flushing a couple of times inhibitor went back in, so i don't think there are any issues with sludge etc....

1. Turn the roomstat down; rule of thumb says every degree is 4%
2. Reduce the amount of hours the ch is on; 10% less time is about 10% less gas.
3. Reduce draft; doors, windows, open staircases and old chimneys create huge heatlosses.

1. Yep get SWMBO some more jumpers me thinks
2. We tend to just use the room stat to control the heating, there are no timers involved, is that a good idea?
3. All chimney breasts are gone during renovations, we do have two open stair cases, i guess shutting room doors in the winter will help? The only drafts i have are when the trickle vents are open, apart from that pretty well sealed house.

 

[bengasman]

2. We tend to just use the room stat to control the heating, there are no timers involved, is that a good idea?

Very bad idea.

3. we do have two open stair cases,

Wild guess says that that will add 20% to your bill, if not more.

 

[AdrianMealing]

Very bad idea.

Can you expand on this please? Is it because we are not keeping a consitant background temperature and therefore heating from scratch?

 

[JohnD]

If you don't have timers, do you turn the heat on when you get out of bed, or what?

A timer will turn it on prior to the time you need the house to be warm, and turn it off prior to the time you can let it cool down.

Knowing the size and construction of your house, and the heat-loss measures you have already taken, is essential to deciding if your usage is normal.

Heat loss is proportional to (heat difference between indoors and out doors) multiplied by time.

So the greater the heat, and the longer you leave it running, the more it will cost you. It is a myth that 24-hour heating is cheaper than heating while occupied. However if your rads are small, or your boiler is underpowered, or your insulation is poor, it may take a long time to heat up from cold; and if anyone likes to drape wet washing about the house or dislikes ventilation, it will get condensation.

As you already have a room stat, you could sensibly replace it with a programmable thermostat, which includes its own timer and can be set for typically 6 periods a day with a different temperature setting for each, and will also have facilities for e.g. a holiday setting where it just protects against frost for a number of days of your choosing, then goes back to normal heating the day before you come home. This is extremely good for comfort and economy. It might cost you £40 or so.

If you are fond of DIY plumbing you can easily fit thermostatic radiator valves for a cost of £10-£20 per radiator, which you can do during the summer months when heating is not required. You can probably do 4 in a day without difficulty, and can do a system clean (using a cleaning chemical, not just plain water or inhibitor) and repaint radiators or repair any leaks while you are working. If you have to pay someone else to do the job it will cost a lot more.

The amount of heat lost will depend on insulation of loft and cavity walls if you have them, plus draughts. If you have large areas of glass such as patio doors and conservatories, or bare uncarpeted floors, they will lose a vast amount of heat.

If your rooms do not have closed internal doors, a lot of the warm air will rush up to the roof and it will be very difficult to make the rooms feel comfortably warm. The same will happen if you have holes in the ceilings for downlighters or pipes.

Ornamental gas fires waste vast amounts of energy.

How many cubic metres of gas per year have you used in the last twelve months, the previous, and the one before that (if your gas account is online you may be able to view the meter history there)? For example I have a larger house than you and used 1105 cu metres in the last 12 months. There are roughly 11kWh per cu metre so I calculate you have used about 1596 cu m in the period you mention which seems excessive. I pay about 50p on average per cu m.

Be aware that women always complain of being cold at intervals not exceeeding 45 minutes, so buy some thermometers and find out what temperature the rooms are actually being heated to.

I am a householder not a pro.

 

[AdrianMealing]

Thanks John, you could not have read my previous posts regarding TRV and insulation. I have already mentioned it above, and have these installed to the max.

However i already have a stat which is wireless to the boiler, we leave this at a set temp during winter and different during summer (in fact off), so it kind of looks after itself most of the time, the only time this changes is when we want to boost the heating and increase the temperature in the winter. I don't see the point of setting the temperature for differing times of the day when the set comfortable temperature looks after itself.

The stat is capable of timed programming, but has never been used this way.

It's looking like the upshot is close the internal doors in the winter, set each TRV for each room and buy some more jumpers!!

 

[JohnD]

I don't see the point of setting the temperature for differing times of the day when the set comfortable temperature looks after itself.

If, for example. you were out of the house from 8am to 8pm, there would be no point in keeping the house hot while it was unoccupied, this would just be topping up the heat that leaks out. For people who are out during the day, it is more economical to set the timer to come on at (say) 6am so the house is comfortable to get up in, and go off at (say) 7.30 so it is not kept warm when unoccupied; then come on at (say) 7.30pm so it is comfortable to come home to. No gas will be used during those empty 12 hours, giving a considerable saving. If the night-time temperature is set back by say 5C, less gas will be used while you are tucked up under the duvet.