Best way to operate central heating?

[Rich114]

Hi,

After some advice hopefully if anyone can help.

Just moved into a detached house, which is costing a LOT in gas bills, so I just wondered what the best way was to be operating the central heating (radiators with combi boiler). The house gets relatively cold as it doesn't get any sun in it at all, but is well insulated and has uPVC double glazing.

We've turned the boiler's hot water temperature down to as low as we can live with it.

What setting should we have the heating dial to on the boiler?

There's a wireless thermostat in the living room, which is set to 19°. There are 2 large radiators in the room (quite a small room really), which have their thermo valves removed (so effectively not temperature-controlled, turned only on/off by the main thermostat), and have radiator cabinets over them. They get very hot, and you often have a blast of hot air when you walk in the room, even if the doors are open (they usually are).

We also have a separate dining room, and we keep that radiator on 3, and the door shut during the day. This has the effect of making the room almost ice cold when the doors are shut for some reason, so if we know we're going to use it, we have to keep the doors open for a bit to heat it up.

All other radiators in the house (inc. hall/bathrooms/kitchen) are set either on 2 or 3 depending on their purpose (kitchen has a cabinet over it, and is set to 2); and master bedroom door is closed during the day as we have a dog that we want to keep out of the room. All other doors in the house are either open or pushed to (but not closed).

Heating comes on at 19° half an hour before we get up, and goes down to 16° half an hour after we go to bed. If we're out for the day, we turn it down to 17° before we go out. I work from home in a room I use as an office, so unfortunately need the house heated during the day, though obviously not the upstairs (though I don't really want to be messing about with the radiator thermo valves upstairs every day).

So, I guess my question is: what can I do better to significantly reduce my heating bills?

-What setting should I have the actual boiler dial on?
-Is it best to have the wireless thermostat situated in the living room all the time (inc. during the day when I'm working in another room)?
-Am I right to have removed the thermo valves from the 2 living room radiators (that are in cabinets)?
-Is the temp setting of 2 on radiators in e.g. the bathrooms/hall/landing/kitchen okay; with bedrooms/living room/dining room/office on 3?
-Is it okay to have most of the doors open, or better to keep individual rooms closed?

Any help would be greatly appreciated. We had a plumber round before Christmas, and asked him for advice, but he didn't have anything at all to offer, so hopefully someone on here will have some experience and knowledge!

Thanks in advance.

 

[Dan Robinson]

all that info, yet no mention f the boiler make and model, age and type of system nor what type of thermostat and timer.....

 

[Rich114]

all that info, yet no mention f the boiler make and model, age and type of system nor what type of thermostat and timer.....

No need to be condescending! It was more general advice I'm looking for, rather than model-specific information. Just how a central heating system should generally be operated to be most effective and economical, regardless of the specific model of the components.

It's a gas central heating system (standard radiators) with a combi boiler, installed in the past few years and regularly maintained, with a single wireless digital thermostat, that includes a timer with 5 time settings. I'm not at home at present, hence can't get you specific makes/models of the components; though I'm not sure why that would be specifically necessary, given the generalisation of my questions?

 

[Dan Robinson]

Fine, I'll take my free professional advice and pheck off somewhere else.

Goodnight.

 

[Rich114]

Fine, I'll take my free professional advice and pheck off somewhere else.

Goodnight.

No worries, I would rather pay someone to genuinely help in a friendly, "professional" manner; rather than get "free, professional advice" that apparently has to come with an attitude...

 

[muggles]

How well insulated is the loft? This can make a huge difference, try to get 10-12" up there. Buy insulation from Homebase, it was £5 a roll last time I looked.

When was the boiler last serviced?

The boiler's hot water temp will have little effect on your overall gas bills, as hot water accounts for only about 10-15% of the total, the rest goes to heating your house. Turning the heating side down a bit will help, but of course the central heating water does need to be warm enough to heat your house!

Take all radiator cabinets out and throw them away, they waste a lot of energy.

The valve pin on the dining room radiator might be sticking, causing the chill in that room.

If you have specific days when you know you're going to be out, for example every Tuesday, then you should be able to program your heating to just be on in the morning and evening, and off during the day. It is possible to get electronic radiator valve heads that are individually programmable, but at around £25 a head they might be more than you want to spend.

The wireless room thermostat should be fixed to the living room wall 1.5m off the ground. It's not designed to be moved around.

The temperature setting of individual valves is entirely down to what you're comfortable with. Lower will use less heat, but might make you cold.

If you want different temperatures in different rooms, keep the doors closed. If you want the entire house to be the same temperature, leave them all open. Try to close upstairs off though or all you heat will go up there first, as heat rises.

Hope this helps!!

 

[Rich114]

Many thanks for your lengthy reply Muggles, it's appreciated.

I'll have a good read through your reply, and will get back to you shortly (if you need me to!) when I'm back home!

 

[Rich114]

The loft looks to be relatively well insulated, but I'll see if it's 10-12" as you recommend, thanks.

The boiler was serviced just 3 months ago.

Is it better to have the boiler on lower, and the thermostat on higher, or vice versa? And where do the individual radiator thermostat valves come into it; again, should the radiators be as high as possible, and the main thermostat as low as possible, or vice versa?

Thanks for the advice re. radiator cabinets, I will do just that!

I will look at the dining room valve pin, thanks.

I'll happily look at radiator valve heads if they're only £25, sounds like a good suggestion, e.g. to turn off the radiators upstairs during the day, and the living room, while I'm only basically using the office, kitchen and downstairs toilet?

The thermostat in the living room is on top of the mantle piece (we never use the fire), so I'll keep it there.

The valves are set as low as we can stand them in each of the rooms, that keeps the rooms at a steady, comfortable temperature throughout the day.

I'll close all the doors upstairs as you suggest; and we tend to like the whole house at the same temp (kitchen can be a bit colder due to cooking, and hall can be colder as you just pass through; but to save having to open/close doors all the time I'll probably leave it all the same).

Thanks for your advice, it's really helped. Large gas bills coming through aren't much fun to see, but as long as I'm doing all I can to control it, I'll be happy...

 

[ALEC1]

TRVS aren't as good as people think...the boiler keeps thrashing away at set point and if all the valves are shutting down the boiler pump takes stress it wasn't designed for.

If its an old cast iron boiler it will tolerate this well but reduced flow through condensing boilers is not a good idea...

If it is a modern condensing boiler I would see if you can add a modulating room controller...this varies the flow temperature according to demand (the cooler the room, the warmer the water in the radiators!)

if its a big house and a modern condensing boiler then weather compensation as well is a good idea...

 

[D_Hailsham]

Is it better to have the boiler on lower, and the thermostat on higher, or vice versa?

Set the boiler thermostat to 75C and let the room thermostat control the boiler. That way the house will heat up quickly from cold and the room stat will maintain the required room temperature.

where do the individual radiator thermostat valves come into it; again, should the radiators be as high as possible, and the main thermostat as low as possible, or vice versa?

The radiator thermostat controls the room temperature, not the water temperature. The room thermostat turns the boiler off when the room it is in reached the set temperature. If the room stat turns the boiler off too early, the other rooms will not reach the temperature set on the TRVs.

 

[muggles]

I'd set the boiler stat to no higher than 70ºC, preferably 65ºC or even 60ºC if you can get away with it, this will encourage it to run in the higher-efficiency condensing mode more of the time (condensing boilers don't always condense...). Ideally there should be a 20ºC difference between the flow and return temperatures on the boiler. If you tell us the make & model of your boiler when you get home, we'll be able to advise on ways that you might be able to further increase its efficiency, combi boilers tend to be over-rated for heating in the houses they're fitted in and need the power of the heating turning down on them, something that is not often done.

The rad valve heads I was talking about are these ones http://www.saveonheatingbills.co.uk/index.html If you find you have got valves that are sticking it would be better to replace the entire valve rather than just the head. The radiator stats control the temperature in the individual rooms, so they should be set to the number that makes you feel comfortable. This has absolutely nothing to do with your boiler thermostat, which controls the temperature of the central heating water leaving your boiler.

 

[Rich114]

Thanks for all your help guys, and sorry for the delay in replying!

The boiler is MAIN Combi 24 HE.

I was advised to remove the thermo valves on the 2 radiators in the lounge (the main thermostat is in the lounge), but our gas usage has significantly increased (3x) since around the time we did this - other factors are probably affecting it as well - so perhaps this wasn't the best advice?

The boiler unhelpfully doesn't have temperature markings on it, just a dial, which is currently about 75% of the way to the top (and always has been), so I'm not sure what that will translate to?

So, in summary:
-Make sure 10-12" insulation in loft
-Room thermostat (in lounge) as low as we can stand it (currently 18.5°)
-Each radiator as low as we can stand them
-Remove radiator covers in lounge/kitchen, [and put thermo valves back on, set to 3 as the others are?]
-Consider timer valves on radiators we don't want on all the time (e.g. upstairs)
-All doors closed upstairs (I'd prefer to leave downstairs doors open during the day, but we close the lounge doors in an evening, where the room thermostat is)
-See if valve in dining room (that is often cold when door shut) needs replacing

If I turn the boiler thermostat down, does that not mean the radiators will take longer to heat up, and therefore longer for either/or the radiator/room thermostat to reach the required temps and turn off again? What's the best way to work it: just everything as low as possible, or would it be beneficial to have the boiler on a bit higher so everything heats up quicker, and is therefore on for a shorter period of time?

 

[ALEC1]

people who have tried claim that heating a house 24/7 is more economical than switching it on and off the whole time but these are the type of people who always have someone in the house all day...of course it is relevant to occupation rates...

so if you only want heating in the morning for a couple of hours and then in the evening for 6 or 7 then I would run the boiler at lower temperature.....say 55c or 60c. If its very cold then raise the temperature of the boiler...

No only does it increase boiler efficiency, it also limits over shoot which overheats the rooms then as it cools down you reach for the thermostat to turn it up again...

 

[Rich114]

Thanks Alec,

I've now removed the radiator covers; replaced the thermo valves on the 2 lounge radiators (where the room thermostat is), both set on 3 so slightly above the 18.5° of the room thermostat; reduced the temperature of the radiators in some of the rooms we don't need as hot. I'm also going to get a couple of the timer radiator valves (thanks Muggles) for the rooms I never use during the day, and will keep the doors of those rooms shut so the cold air doesn't escape. Would it be advisable to just reduce the temp on those (e.g. to 10° when not in use), or is it okay to turn them off completely when the rooms aren't needed; what's the most economical way of doing it?

During the day (I work from home), I'll keep all upstairs doors shut. The only rooms I really need heating 9am-5pm are the office (small room) and the lounge for my dog. As I rarely use the kitchen during the day, would it be advisable to close the kitchen door (would that use less heating than if the door was left open)?

And, the office goes straight to the hallway, then through to the lounge. I'd rather keep the office/lounge doors open so my dog can come and go out of the two rooms; but, would keeping both the office and lounge doors closed require less heating/gas?

Thanks for all your help guys.

 

[plumberdan]

Sure you don't have a small gas leak that you can't smell, just wondering as you said you had a large bill out of the blue without really changing anything substantial like electric cooker to gas etc.