Education Central Heating Bills!

Right, I am in th UK, just moved in to a new student house, and have a little question thats eating me.

The ladies and Gentleman I have moved in with (4 other people) have decided they are not going to use hot water any more... because it increases the gas bill too much. So when it comes to washing up and stuff, they boil a kettle to fill the sink and top up with cold water.

My question to all you clever people is...WILL it cost more in electricity to fill a sink this way than using the gas heater to just pour it out the hot tap?

I am certain that OBVIOUSLY the gas bill will drop...but the electricity bill will increase the same if not more?

WHAT YA RECKON!?

 

Depends. What kind of gas boiler have you got? Instant? Storage tank?

If you've got an instant gas water heater then almost certainly it'd be cheaper to use that than use a kettle. However, if you're using gas to heat 200 litres of water in a tank in order to only use 10 litres to wash up with (and assuming that is the only thing you would be using a hot storage tank for), then it'd be cheaper to use a kettle.

Don't forget also that a gas boiler (instant or otherwise) will heat water to 70-85C, where as kettle will boil the water.

When I was at uni, an instant gas heater cost us about 400 quid to run for 10 months - for showers, washing up, etc etc etc. 400/5 = 80 quid / 10 months = 8 quid a month for hot water each.

In any case, your house mates are retarded if they think that washing up will increase the bill by a lot of money ... if you've got an electric shower ask them to work out how much that costs to run for half an hour a day for 5 people take a shower and they might get a shock

I reckon they need to learn how to budget

 

Typical, students that don't shower

We had hot water, and never had a problem with paying the bills. Unless your bills are sky high, which I would suggest is something wrong with the system.

 

using a kettle... that's just daft..

 

bills will be cheap if you don't use heating full blast through winter. Get a cheapo electric one

 

Aye, if it's a Combi, or Condensing Combi, then it'll be far far cheaper to use the boiler. If there's a water tank in a cupboard somewhere (it'll probably be fully lagged) or up the loft, then, as RTT mentioned, you're better off using a kettle.

 

The simple fact of the matter is that in terms of raw energy, gas is priced cheaper than electricity. Electricity will cost you in the region of 11p per kWh and Gas will cost around 2 or 3 pence per kWh. Ignoring efficiency, it's going to be cheaper to heat water using gas

Proof (heat 10l of water by up to 80C from 20C room temperature)

Energy required: amount water (L) * temp change (C) * energy required per unit change (J)
= 10 * 60 * 4200 = 2.52 MJ or 700 Wh or 0.7 kWh

To heat those 10 litres using electricity: 7.7p (11 * 0.7)
To heat those 10 litres using gas: 1.75p (2.5 * 0.7)

assumes 100% efficiency though

As Kenko and I said, it depends on the boiler you have. If you are heating water on-demand, for gods sake don't use the kettle. If you're having to heat a storage tank up and you only use water from that tank for washing up, the smart decision is to turn off the boiler and use the kettle. End of

 

Eek, i dunno about boilers. I feel a bit daft.

Basically in the kitchen there is a Glowworm Spacesaver Complheat! It is a big (Spacesaver pfft!) white metal effort with a pressure guage, and a temp guage.
Then on the wall beside it is a thermostat thing that has

Clock - ON, OFF, ON, OFF, SET
Central Heating - OFF, CONSTANT, TWICE, ONCE
Hot Water - OFF, CONSTANT, TWICE, ONCE

That is pretty self explanotory to use, but if I put Hot water on constant...what does it do? Is this a combi boiler? does it like keep a little tank of water inside it hot or what? I think it will be fairly old cuz thats what ya get for being in a student house! But hmm?

I feel a bit stupid really now. I have never had to deal with these things before! I lived in halls before this!

 

When you turn the hot tap on in the kitchen does the boiler fire up?

 

It sounds like it heats up a big water tank somewhere, tbh.

 

Are they gonna wash there hands in cold water too ? :S And does your central heating run off electrically heated water ?

Sounds like a **** plan to me, just tell them to stop being so damn stingy - students dont have to live like hobos, we aren't /that/ bad off.

edit: i see you can heat water and central heating seperatele, in which case its probalbly an on demand thing imo - in which case heating the kettle owuld both take longer and be more expensive.

 

This gets complicated, as if you run your hand down the cylinder you'll find it's hot at the top and cold at the bottom - hot water rises. So if the system is on a timer, you don't need to heat the full volume of the tank. The cylinder water also shouldn't go much above about 50C or it's scalding hot (also the hotter the water, the greater the heat losses).

With hot water on tap you're paying for convenience, and it's certainly cheaper if the five of you were bathing regularly, but for the odd bit of washing up the kettle will win.

You seem to have got a fairly decent controller, so use the timer; don't leave it on all day & night or you'll have some real high bills.

 

Yeah, i know how they work. 50C "seems" low but I guess i only really ever use hot taps on the middle-ish setting, so it'd be around 50C.
Ours on the other hand is "hardcoded" to 85C - i'm not even kidding.

Completely stupid systems if you ask me - slow to heat up and not enough hot water in 'em Those instant-gas things are far superior.

 

THey have just turned the central heating OFF! Central Heating and Hot Water are set off.
When I turn the Hot Water to Constant, the boiler fires up and starts making the usual noises, and just kinda carries on for a while. I only left it going for a few minutes cuz I didnt know what it was doing or whether it was filling up some mofo tank somewhere (which i cant find).

I hate stingy students argh! I gotta make them see the light about this!

 

Get a gas meter.

 

There's two schools of thought - below 50 is safe for young kids, over 60 kills most bugs. Your place worries most about bugs.

 

I can certainly recommend a condensing combi boiler. The one I had put in last November takes about 10-20 seconds of water (fast flowing or a mere trickle) to get up to 55c. I still can't get over the availability of hot water - the previous boiler was original to the house being built (1989) so had more than served its time and it struggled to put any good amount of hot water out (blocked tubes I reckon) - it now probably lives in a skip in China.

 

Sounds like a normal tanky boiler to me from your description of the thermostat, combi boilers do water heating automatically when you turn on a hot tap. Turning off the central heating is a good tip for saving energy though, if you're cold, you can put on a jumper or put up with it, and turn it on if it's really cold, in our student house we have the heating on for an hour in the morning and in the evening, and and an hour heating up water at midday. Although that still got us £80 per month gas bills (with a gas cooker as well mind).

On a related note, do any Cardiff bit-techers have a combi boiler? We had to have our boiler replaced since it was ancient and falling apart and the british gas guy said we couldn't have a combi since the water pressure in Cardiff is crap. Was he feeding a line or is it actually true?

 

mike - go take a look at your gas meter (if you have one), does it work in 100s of cubic feet or cubic meters? If so, I can tell you exactly how to work out what your gas is costing you. You could tell your housemates to leave it on for a week and then you can sit down and show them exactly what it has cost to run.

I agree with the others though, it does sound like you're heating a tank of water up. They are usually placed upstairs in an airing cupboard or similar.

 

How the hell did you manage that? I average about £15/month and when it's cold the heating comes on when needed via thermostat - it's set for two hours in the morning and about five hours in the evening. Granted, it's not continuously on.. I also have a full gas cooker/hob which gets used nearly every day, together with a load of washing each week (hot and cold fed). £80/month just sounds barmy!