How much per hour to run this boiler?

dinkytoy

We have a Potterton promax sl 30 which seems to run full pelt, what does it cost to run?
I know we all pay differently per unit, what calculation can I use to work out my gas usage?
I was told it would cost me less than £60 per month to run but it's costing way more than that.

Cardew

That is a real 'how long is a piece of string question'.

It is a 30kW boiler so in theory it could cost up to £1 an hour. However in practice it will only use a small fraction of that amount.

Although it could appear to be running 'full pelt' the output will almost certainly be modulated - i.e. the output turned down and using much less gas.

The factors that will govern the cost of running the boiler are:

Size of property - bedsit or 10 bed mansion!!

Standard of insulation.

Warmth of rooms.

Amount of hot water you use.

How long in the day you have heating.

It is A rated with a 90% efficiency rating so is likely to be as efficient as most other modern boilers.

System

dinkytoy wrote: »

I was told it would cost me less than £60 per month to run but it's costing way more than that.

Where did the figure of £720 per year come from? If you are sitting at home in your underwear with sweat running down your body, then there is clearly something wrong with your boiler and/ or controls. If not, then the problem is most likely related to heat loss. It is a simple fact that if you set a temperature of 20C, then for the room to remain at 20C, the heat coming in to the room must equal the heat that is escaping front it. To reduce heat loss, you must improve insulation; reduce air gaps; draw curtains etc.

As a starting point, contact your gas supplier and ask them for what is known as the Annual Quantity (AQ) for your property. This is property-specific usage data held by the data collectors. The AQ is the past usage adjusted for temperature to give an average Annual Quantity.

PS. As I am sure you appreciate, you will use about 70% of your annual gas consumption during the Winter months. I am using about £42 per month of gas now compared to £13 in June.