Worcester 40CDI Boiler Question

[iomcb1988]

Hi,

We've just moved in to a new house with the above boiler.

It's connected to two big tanks for the hot water.

Our problem is that we've just got a massive gas bill (basically it's £250 per month at this rate) and we need to bring this down drastically.

I've looked for a user manual online and all the manuals show two control knobs (CH and HW) but having looked at ours ... it only has the CH one but no HW - we do have a control panel in the kitchen for hot water but we don't really know how it works.

Does anyone have any idea how this system works, it's so different to things that have been in other houses we've been in.

Will turning down the knob on the left affect our hot water?

2) Any idea how you're supposed to regulate the hot water?

 

[ianniann]

Just to clarify, is this what you have in front of you?

 

[iomcb1988]

Hi, thanks for the reply.

Yes!

 

[iomcb1988]

my question is how does the left hand control affect the hot water?

 

[simond]

Sounds like you have a 40CDi conventional. We fits lots of these.

The single knob sets the boiler output temperature, this is the touch temperature of your radiators.

Turning this knob down will make a small difference to the energy consumption, if you turn it down below around 65C you may find your HW does not get hot enough.

Your question regularly appears here in cold weather. Ways to reduce your heating bill are;

Better insulation of the property
Lower living temperatures (not so good)
zoning of the areas heated so only ones occupied are heated to occupational temperature.


It is always the boiler which is blamed. But remember, you are meant to decide where the heat goes and how hot the house gets.

We are keen on a produict called Hometronic which divides an existing house into up to 16 zones of separately controllable heating.

It is not cheap to put in but allows heat to be used in a sensible way.

 

[ianniann]

Lots of differences in detail, but the basics are:
- that knob controls the maximum temperature of the water in the radiators;
- it also controls the maximum temperature of the water in your cylinder;
- there should be a separate thermostat on the cylinder which controls when it needs more heat and may limit the temperature to a lower value (but usually can't get it higher than what the knob says);
- the control panel in the kitchen is probably just to set the times when the cylinder is allowed to be heated.

It is unlikely to be the boiler itself that makes you bills so huge. You should do a rough calculation of the expected heat requirements for your home and then we can offer ballpark figures of what it should cost to heat. Remember it has been crazy cold recently, but 250 quid is still a lot for one month. Lack of insulation, cylinders in the loft especially with poor insulation, and big houses, can all eat up the gas. Prolific use of hot water can hike your bills too, but that tends to add tens of pounds a month, not hundreds.

Another thought is gas fires. If you're using them for a significant part of your heating, rather than the boiler, you could easily be doubling your bill.

 

[iomcb1988]

thanks so much for your reply.

it's a rented house which has recently been completely gutted and refurbished with all new insulation.

we've had it set to come on for an hour in the morning and an hour in the evening. and the water to do the same. Room temp is at 15 degrees

the house is zoned into two and we've tried to utilise these.

given that we've done the above does our bill sound rediculous? It's a 6 bedroom terraced property.

 

[D_Hailsham]

it's a rented house which has recently been completely gutted and refurbished with all new insulation.

It's a 6 bedroom terraced property.

A 40kW boiler is probably an overkill. You can find out what size boiler you should have by using the Boiler Size Calculator.

we've had it set to come on for an hour in the morning and an hour in the evening. and the water to do the same. Room temp is at 15 degrees

Why on for such a short time and at so low a temperature? You are heating the house up twice a day and then letting it cool down. Doesn't make sense!

15C is well below the recommended temperature. My house does not drop that low overnight, when the heating is off; and when the boiler broke down on Sunday the temperature when we woke up on Monday morning was about 16C.