House is freezing, no idea how to warm it up!

ElixiaDragmire

Ok, this is long story.

We bought a house in October, built in 1997 it's detached (our previous one was semi and newer). This house needed a little love as we could tell, a fair amount of diy and little modernization.

Roll on winter and it been a nightmare. We can't get the house over 18° when it 2° outside. Were pretty sure most if not all the front windows have blown. The loft only has 100mm insulation, and after airing the heating system we keep getting more air in the last radiator on the system. I pretty sure it's hydrogen in the system, I hold a candle near it and it popped. We've added a new GRP thermal front door since the old one was warped and had a massive key lock and broken letter please. We've added draft excluders to doors, sealed windows, added thermal blinds and curtains with no improvement. We then assumed the cavity walls must of been void of insulation and had someone out to check and we do have filled cavity walls! The guy said we could top up the walls and ceiling but theres no guarantee it would solve it

We're now at wit's end with the cold. Even with the gas fire on there no massive improvement, we get to about 20° tops!

Were debating on where to start tackling this before throwing money at it, fix the windows or power flush the system. Both need doing but we don't have the money to do both right now. I've even considered that the boiler and radiators aren't powerful enough to heat the house. I did use some basic BTU calculations and there seem to be less heat produced than need.

Heedtheadvice

Extra insulation in the loft is one of the cheapest and best moves.

However, with 100mm already and not getting up to temperature there would seem to be other more basic problems.
What type of property is it, size and general location?

Are all radiators getting hot, and all over them or do they have cold spots?

Is your boiler running flat out all the time or does it switch off periodically (is it on a timer or do you have one or more thermostats)does it give you hot water? Adequately? Power output of boiler?

Can you feel cold draughts?

There will probably be more questions but answering these might help forum posters to help diagnosis

keith969

Before you spend lots of money, have you though of having thermal imaging done on your house? It doesn't cost that much (I got mine done for free by the local green group) and will at least tell you where you are losing heat - loft/windows/walls etc.

ElixiaDragmire

Alrighty in details.

The house is 72 Square metres in total. All the radiators TRVs are on full blast, no cold spots. I bled them and opened the lock sheild values all the way. The one in the back room gets 'air' every few weeks and needs bleeding regularly.
The boilers is 20 years old, convential system, an ideal classic ff40. It's on a timer, 4:30pm to 10:00pm. It's wired so the hot water needs to be on when the central heating is on. If the hot water is off the central heating won't turn on. Now when the CH/HW is on, it's turn on for a few minutes and turn off periodically until 10:00pm. Now when it turns on is kinda misfires too, 2 to 7 clicks before it ignites! The thing that baffles me is, the boiler will turn off and on even though the house hasnt been brought up to temperature dictated by the house thermostat.

Now for draughts, we did at the front before we replaced it. Now it's the bay window that feels cold but no draught. The gas fire thou, that feels draughty. At best I've put a draught excluder up there when not in use but the vents are the top remain open.

The most cold is felt is at the floor. It's cold up to your knees mainly.

Also the thermal imaging idea would be grand! I'd have to find someone who does it the northwest

Hoploz

It sounds to me like the heating system is the main problem here. Fixing blown windows won't make that much difference, nor will a bit of extra loft insulation. if it was only built 20 years ao it should meet pretty good standards, unlike an old listed building which you'd expect to be cold.

If you set the heating to stay on continuously for a day it should warm the place up.

Check whether the thermostat is working properly too - if that is faulty then it could be knocking the boiler off when it gets to 17c or something.

Turn everything right up and check whether all the radiators get properly hot.

Check the boiler is firing continually.

Not sure what you mean you've done already when you say you've aired the system. The radiators might need bleeding separately. Do this when they are on (carefully so you don't get squirted with not water!) even if one of the radiators keeps getting air in it, that would normally only make that room cold, not stop the rest of the house from warming up.

Hoploz

OK I was typing when you posted that!

Defo sounds like a boiler issue.

dirty_magic

Not sure what you mean you've done already when you say you've aired the system. The radiators might need bleeding separately. Do this when they are on (carefully so you don't get squirted with not water!) even if one of the radiators keeps getting air in it, that would normally only make that room cold, not stop the rest of the house from warming up.

I'm sure you're supposed to bleed them when the heating is off, you can actually put air into the system doing it when they're on.

ElixiaDragmire

Ah sorry my dylexica there, by 'airing' I mean I've bled the whole system. When bleeding, I only get 'air' out of one and I do that every few weeks when I notice the radiator has stopped working and made that room an ice box!

I'll check all the radiators are up to the max.

Just remember something that might be key, the previous owner had a new hot water tank installed last summer.

dirty_magic

There's something not right if you have to bleed it every couple of weeks to get it to come on. Have you had the boiler serviced?

Mr.Generous

If the hot water gets very hot turn down the gate valve leading to the hot water cylinder and open up the one leading to the heating to shift the balance more toward heating. The radiator that continually fills with air you could change the bleed valve to an automatic one that bleeds out air on its own.

tacpot12

Having opened all the lockshield valves fully is a bad idea, as the system is no longer balanced. This means that the radiators downstream of the first one won't be getting enough hot water - the water is being returned to the boiler at too high a temperature as it is not reaching some of the rads.

So the system needs rebalancing. The fact the the hot water and heating don't operate independently is probably causing more inefficiency in the system. Although the new cylinder should be well lagged.

I would get a heating engineer to review your calculations of the heat load, and to rebalance the system. The system may have always been too small.