Help me understand our heating...

ganderson1804

Can anyone please help me to understand my heating…?? We have gas central heating.

In the cupboard under the stairs there is a programmer where I set the times and days for the heating to come on / go off and also the hot water.
In the spare room cupboard I have a hot water tank. I’ve never touched this. (been in 3 years)
In the loft I have a cold water tank and a header tank.
The radiators all have thermostats on them which range from 0 – 6.

At the moment our heating is off completely and has been for a number of months. I still have the hot water coming on for 1 hour in the morning and 3-4 hours around 4-5pm.

I have no idea how often I need to have my hot water on…? Its used for a shower for me in the morning – 10mins max. Dishes around tea-time, a shower for my husband and a bath for my daughter every 2-3 nights.

I’m not really sure what I’m looking to ask to be honest… our bills for gas and electric are very high. I think combined £146 a month… so I’m trying to understand the system before winter comes in to try and keep the bills down.

We live in a 3bedroom semi. I don’t really understand how all these things work…

Ebe_Scrooge

First off, is your tank ( and pipework leading to / from it ) well insulated ? If not, get that sorted pronto.

Once that's done, you will probably get away with the water coming on for an hour in the morning and an hour in the evening. This depends to a great extent on the size of your tank, it's a case of trial and error to see what works best for you. So long as the insulation is up to scratch, it should stay hot for many hours, maybe even up to a couple of days, if it's not being used.

Having said that, even if you've got it timed to come on for several hours at a time, the boiler shouldn't be firing up if the water is up to temperature.

But the most important thing is the insulation. If it's not very good at the moment, you can buy purpose-designed hot water jackets, and pipe lagging, from any of the DIY sheds for not much money.

Regarding your radiators, you have what are called Thermostatic Radiator Valves ( TRVs). They allow you to control the temperature in each room independently. So you have the "main" temperature on the room thermostat set at pretty much the highest temperature you want, then turn the individual TRVs down to suit what you want. Often people prefer their bedrooms a bit cooler than the lounge, for instance. And if you have any rooms you're not using, turn the TRV in there right down to zero and keep the door shut. That way you're not paying to heat a room unnecessarily.

getmore4less

Check what temp the tank is getting warmed upto, and check the boiler stat as well.

If you have realy hot water in the morning then a lot will be lost during the day if you don't use the water and insulation needs fixing.

We had ours set so that the shower did not need cold water with the boiler stat set to around 60c(no1).

Seemed to be OK for most things I think the tank was probably getting to around 45-50. A bath would need topping up as it needs hotter water if you want a soak.


We have just installed OWl which has a programable tank thermostat with recording so we can see the temp profile and our usage, not cheap but gives us more control, the heating part has not been tested yet the hous stays warm even overnight when outsides have been dropping.

From the first couple of night our water shows temp going from around 50c down to around 35c over 10-12hours. (time to review the pipe insulation on the pipes connected to the tank as that is where the losses must be. Now we can control the water temp and timing more closely I think we will run the boiler a bit hotter(faster water warmup) and heat the water up on demand for baths.


It may be worth investing is something that gives more control and an energy monitor to look at electricity usage.

Crinkmeister

What gas boiler do you have? Old boilers are not very efficient.

cyclonebri1

Regarding your hot water just ensure the timer is on as short a time to give you hot water when you need it, no longer. And remember it is likely cheaper to use an electric shower if the water is cold than to heat up a full tank. Same thing for pot washing, boil the kettle.

That said I have a relative that has the water heated by a gas back boiler and he finds 1/2 at a high setting is all he needs for the day. The tank is very well insulated, he has completely filled the airing cupboard with insulation.

That's the extreme but I can't see why you need 3 to 4 hours of energy input into the water every evening, it will simply cool overnight

The time to change boilers is normally when they break, not just because they are getting on, "the cheapest boiler to run is the 1 you already have" is often quoted;)

Finally absolutely ensure you are on the right tariff with the right company for your combined energy bills, probably as big a saving as you will make elsewhere.

getmore4less

cyclonebri1 wrote: »

That's the extreme but I can't see why you need 3 to 4 hours of energy input into the water every evening, it will simply cool overnight

It won't be 3-4 hours continuous what will be happening is if water is used then there will be a top up.

The trick will be to time the end of the cycle to be before the last main use.

3-4 hours around 4-5pm

So the OP water could be last heated anywhere between 7 and 9

A tank would probably do the hubby shower, bath and misc use so probably worth making sure that the timer ends before hubbys shower.

If there is a boost button(ours had a 1hour boost) the evening heating could be one tank full for the misc and shower, then use the boost on bath night.

peachyprice

I don't think it's been mentioned yet, but check if the hot water cylinder has an immersion heater attached, and make sure that is off at all times. You won't need it if your boiler is heating your water but it is very common for HW cylinders to be fitted with one as a back up and it is also not uncommon for these to be left on by mistake.

It will look like a deep round disc about the size of an apple on the top or side of the tank with leads that lead to a socket on the wall.

Ruski

Something needs to be pointed out here

Don't forget - you're not actually heating the water for 3 - 4 hours as the cylinder stat will cut in and turn off the boiler.
Once the water is at your desired temperature, very little 'extra' gas is then used.

Personally I would have the water 'on' for an hour in the morning and in the evening - if you don't use much then the re-heat time to temp will be minimal anyway, and probably only 'use' about 1/3 of that time actually firing the boiler (and thus gas usage).

HTH

Russ

getmore4less

Ruski wrote: »

Personally I would have the water 'on' for an hour in the morning and in the evening - if you don't use much then the re-heat time to temp will be minimal anyway, and probably only 'use' about 1/3 of that time actually firing the boiler (and thus gas usage).

HTH

Russ

Since we installed OWL which records the tank temp(at the same place the old tank stat) we can see warm up cool down times.
(as you draw water the bottom of the tank drop but you still have hot water higher up)

we can also see we have an airing cupboard that is getting very warm so that's heat losses from the water, time to insulate more of the pipes.

I think if you have the boiler temp up you can control the amount of hot water by having the timer stop the heating before the tank stat.

So for the OP that just wants a shower in the morning could start reducing the heat time till there is just enough hot water for the shower.
(the time may need tweaking as the incoming water temp drops in the winter)


I wonder if there is a market for a tank temp recording system to add to existing heating systems, two stats one placed near the top and another near the normal stat could be use to record the heating/usage so people can optimise their system.

might be an overkill, not cost effective, once the main heat losses are tackled there may not be much to save.

Horseunderwater

Our gas use has gone down significantly since I started heating water half hour in morning 20 mins at midday & half at around 5. The heating times are 4 hrs 10mins early hours, 1 hr lunchtime & 6 in evening - used to be 17 hrs before that. Just had a new boiler fitted totally free, so I hope we will save more next year. Loft insulated fully - hw cyl has thermostat set at 55 & now comes out at 65 in the bath etc. It's lagged.
All water fill appliances are cold fill only, but you can turn off a hot water pipe if both attached using the small tap valve, save hw & excessive leccy used to cool water down.
New dbl glazed windows doors.
TRV's on all but 2 rad's & most of those set at 1 or below. OH tells me it's so hot upstairs now that he needs a fan on! So far we are down 4000kwhs or £200 on the prediction statement. We have dual fuel discount & get nectar points. Brit gas PPM's - no debts on them, so I have them by choice as I do not like anyone else debiting wild amounts of cash from my bank. Shortly DD will be off 2 uni, so bill should go down a little more.

cyclonebri1

Ruski wrote: »

Something needs to be pointed out here

Don't forget - you're not actually heating the water for 3 - 4 hours as the cylinder stat will cut in and turn off the boiler.
Once the water is at your desired temperature, very little 'extra' gas is then used.

Personally I would have the water 'on' for an hour in the morning and in the evening - if you don't use much then the re-heat time to temp will be minimal anyway, and probably only 'use' about 1/3 of that time actually firing the boiler (and thus gas usage).

HTH

Russ

Accepted, I shouldn't put it like that but unless the OP shower after midnight it's far to long. 4 hours at 90% eff costs more than 1 or 3 at the samerate regardless

Aim to leave only warm rather than hot water when you go to bed, I think you'd be surprised how much that will save you.

The critical bit has been touched on several times, max out the insulation to the hot water cylinder, 1 thin jacket is totally inadequate.