Central heating. Cold house.

[user1495832265]

Boiler is around 10 years old. Worcester Bosch combi. Can get model name/number if it helps.
Radiators were not replaced at the same time as the boiler for some reason, I believe they're at least 20 years old. All have TRVs except the bathroom one which is newer, one of those vertical ones.
The house has old double glazing, again I'd say it's around 20-25 years old.

I realise it's rather cold at the moment but the house isn't really warming up very well. One bedroom heats up nicely within an hour or two of the heating coming on, gets to 19 degrees and stays there.
The worst room is the sitting room. The heating has been on in there all day now and the temperature is still only 19 degrees, it was only 16 degrees first thing this morning before the heating switched on. The radiator is very hot to touch so I don't think it needs bleeding (?)

I moved into the house a couple of months ago. Have never had a problem like this in previous houses. This one does appear to have been rather neglected over the last decade or so.
Any suggestions before I get a heating engineer in?

if the rads are hot then are they just not big enough for the room??

Bump. I'm having the same issues with mine too. But my bedrooms don't heat up well but the living room does. Then within turning the heating off the temperature drops quickly. Like yours the property has been neglected before I moved in

Is there a thermostat in a room somewhere? Is that room hotter or colder than the sitting room? Have you tried shutting doors on unused room? Have you got the radiators at different TRVs?

Does the room have a big patio door, large bay or other large windows?
My lounge has all three and it is always colder than other rooms as you lose so much eat through the glass.

A few issues have been pointed out here, I think I see the problem now.
The sitting room is quite a big room, and there is only one radiator. So it could well need another, but there's no space for one due to the layout of the room. May have to get a portable heater of some kind in there.
It does have a large window, floor to ceiling and about six feet wide too.

Gizlots no room thermostat, all works on TRVs and the timer on the boiler. The TRVs are all set to different levels. I've turned one up in the hall as it was chilly in there too. Should they all be set to the same? I had Hive in my last house and it was so straightforward to use. Hopefully can look at getting it installed here before next winter!

Do you have good thick curtains? If you don't, off to the charity shop quick. If you do, close them as soon as it gets dark.

Maybe your last place had cavity insulation and this doesn't?

I've had the same problem downstairs in my new house, freezing while upstairs was like a sauna.
I had a brand new boiler fitted before I moved in.
My OH has changed the downstairs radiators from single to double panels with 10000 btu.
Also the loft space had no insulation or pipe lagging which he put in yesterday.
The difference is amazing!
Next job will be new windows but in the meantime we've taped up the edges.

Watch out for heating rooms you're not in as you could be going to run up bills, and sounds like the heat is just going straight out again! Better to have it turned up just before and while you are in the room (realise you may be in all day anyway of course)

Decent curtains with rails not poles. Not farty frilly jobs, lined opaque curtains. Drawn at dusk, opened at dawn.

Except you have a stupidity with a floor to ceiling window. Not sure how you cover those.
Draught excluders.

If you don't light a fire check is there a draught coming down the chimney. I put a chimney balloon up my chimney last winter and the difference it made is amazing.

it's quite often because the radiators are undersized. This is often because it makes the installation price look a bit lower.

First, verify that all of them are "too hot to hold" at the top, and "too hot to hold for long" at the bottom.

You mention that you have no room thermostat. This will not prevent the house getting warm, but it is uneconomical.

Please measure the radiators you have. With luck they will all be the same height, perhaps 600mm or so, so measure all the lengths and add them together. Treat doubles as 1.8 times the length. Calculate how much heat the radiators can deliver into the house. It is very unlikely your boiler is undersized. You can estimate the total heat loss of the house using this calculator

For the room that seems coldest, please say the size of the room and the size of the radiator, as a sample, and how many external walls it has, and how big the window is.

A one-metre long double radiator has a nominal output of about 1800watts

A one-metre long single radiator has a nominal output of about 1kW

Real heat output is less

Do you have CWI?

Are you keeping the internal doors shut?

Special You buy long thermal lined curtains from Amazon. We have a set of single glazed French doors in our current rental, with a 274 cm drop. I found a pair of not too horrendous neutral chenille thermal lined curtains, which I will pick up when in UK next week, and bring back to Belgium to hang up from the curtain pole. It will keep my Mum amused for hours putting hooks through and pulling the cords up on the curtain tape.

Things we did in my v cold house with a noticeable difference after each:

Powerflush
Replace all radiators with doubles, larger size in possible - look to see if extra rad can be added if room is massive with only one radiator
Chimney balloon if you don't use the chimney
Get windows refurbed (I can't have double glazing) to prevent heat loss
Thermal lined curtains
If no options for extra radiator and you have a chimney, wood burner stove.

So far it's been a 8 yr project but some of these are v quick wins and you are looking at one room. For me, it was the whole house!

Change your rads. We changed ours from ancient single ones to doubles and the difference was absolutely incredible.

But if the windows are floor to ceiling where does the rail go?

Anyone living in the UK can get curtains from charity shops, or companies that pay tax.

Our house is Victorian with single glazed windows in a conservation area (so we can't change them easily). We have thick, interlined curtains, which makes a difference, but the most effective thing is keeping the doors to all the rooms closed. The hall, stairs and landing are freezing, but the actual rooms are much warmer (and we don't tend to hang about in the hall).

specialsubject: you can get curtain tracks that are screwed into the ceiling.

Radiators vary wildy in terms of their output. If you have old-fashioned single panel radiators, they are massively less good at pumping out heat than newer, bigger models.

Work out what BTUs you need for the room:

soak.com/info-btu-calculator

Then get a radiator with more than that number!

Agreed with pps that the radiators don't match the heat loss of the rooms. 2 small is better than one large, but fit what you can.
The other way round is to go round with a Jos stick and see where the draughts are, you may have a lot more than you think. Also insulation, especially loft insulation as it's cheap. Wall insulation is effective but expensive. Floors should be draught free, insulation there is a bonus.

Thanks to everyone for lots of great advice on this.
Will be discussing with OH about a few suggested changes, especially newer/bigger rads where needed.
I'll update on progress in a few weeks.
And it's much milder outside today, woke up in the night too hot!

Oh I forgot loft insulation. Also check round your loft hatch - we had massive drafts round that and it was just made of plywood. Now have an insulated loft hatch and beefed up the layers of loft insulation.

Make sure your walls are properly insulated. You can gets grants etc, get the boiler serviced ask about the radiator size.
I live in a graughty 1930's house with ancient double glazing and the best way to keep it warm is to have the door closed between each room, no open plan for me thanks.
Then to have thick curtains everywhere and a door curtain. My granny lived in a freezing grade 2 cottage and her thick velvet curtains kept the heat right in in winter.
I have thick throws on all the sofas too and it's nicer to throw one on while watching tv than to crank the heating right up.

Double radiators may be an option or a couple of vertical ones. You usually need to have them near to the window as that's the coldest part of the room.

We moved into a freezing house that is now warm. New boiler and massive rads. Also a dehumidifier to remove damp. Plus a nest to set a minimum night temp so it never gets too cold.

We also had it double glazed and new carpets with thick underlay. More loft insulation etc.

Did gradually but it's transformed house.

The plumber could not believe the size of rads I wanted

We have new radiators in three rooms in this house and older radiators elsewhere. The new radiators are triple victorian style column radiators. The old ones were single panels. The difference is amazing. The kitchen, snug and bathroom where the new radiators are heat up really quickly and are toasty within 15 minutes of putting the heating on. The rest of the house takes much longer to heat up.