How much to run a bath? - combi boiler

Muppet81

Could anyone give me a rough ball park figure of the cost of running a standard bath (like it fairly full) with a combi boiler?

Thinking of replacing our existing obsolete boiler with a combi.

How does this compare with the cost of 1kw electric shower? I do tend to stay under it for about 5 mins which I know is costing fortune but love to be warm

Wondering if having a bath (even a half full one) each day might work out cheaper?

HappyMJ

Muppet81 wrote: »

Could anyone give me a rough ball park figure of the cost of running a standard bath (like it fairly full) with a combi boiler?

Thinking of replacing our existing obsolete boiler with a combi.

How does this compare with the cost of 1kw electric shower? I do tend to stay under it for about 5 mins which I know is costing fortune but love to be warm

Wondering if having a bath (even a half full one) each day might work out cheaper?

You don't have a 1kw electric shower...

It's more like 8.5kw or 9.5kw. It does not cost a fortune as you say it is only for 5 minutes so it's quite cheap. If I assume for ease of calculating that it's 6 minutes then divide the kw rating of your shower by 10 then multiply the figure you get by the secondary rate on your electric bill and you will know what a shower costs.

A gas boiler is harder to work out as you have efficiency calculations to calculate too. Generally new condensing combi's are around 70 to 80% efficient when heating water for instant use (they are not condensing for high water temperatures). You would need to find out how much water is needed and what the temperature rise is to figure it out. It isn't easy to figure out.

System

Ive bought myself a new toy. Its an OWL energy monitor which is all set up and working. I was surprised to see that when i ran my bath the electricity consumption went up too slightly. Hubby reminded me that combi boilers dont just run on gas.

zippychick

as this isn't Old Style, ive moved it to Gas and electricity board.

Zip

penrhyn

With a combi your hot water is at mains pressure, therefore the best solution is to replace the electric shower with one that works off the combi.

Farway

penrhyn wrote: »

With a combi your hot water is at mains pressure, therefore the best solution is to replace the electric shower with one that works off the combi.

I have a gas combi boiler, and only use shower. It is great, but do make sure you get a thermostatically controlled shower, cost is more, but not suddenly having a cold shower as the washing machine / dishwasher, etc fills will immediately pay for itself :eek:

macman

Gas is around 1/3 the cost of electricity per kWh, therefore a bath will be 1/3 of the cost for the same volume of hot water.
But since you probably use about 1/3 of a bath's volume for a five minute electric shower, it's quits.

Muppet81

Some good advice here. Especially thermostatically controlled shower. Thank you all very much. I have an OWL which came free some time ago. Good idea, I will ge it rigged up