Insufficient Heating

Wrake

silvercar said:

We had one room colder than the rest. We turned off every other radiator in the house and left the offending radiator on for a couple of hours. That seemed to improve things. when we turned the other radiators back on, the heat distributed more evenly.

Yeh tried that on advice early on but no difference

Wrake

ThisIsWeird said:

Wrake said:

Sorry the radiator itself. Room just doesn't get warm using the 2 fixed radiators.

I haven't checked the temperature. The other downstairs room (where the thermostat is) struggles to get to 19 and the other room is colder. With the electric heaters I'm unsure of the temperature but I'm fairly confident it would be above 21.

I believe the central heating is working as intended and it is just down to poor design.

The last thing I want is to start making a nuisance of myself but I wanted to make sure there was nothing obvious that the LL had been neglecting in their duties - essentially is it the house's fault, not the LL's?

I wouldn't start trying to balance radiators - you can get yourself tied up in knots, and it isn't for you to do in any case. But, provided you mark exactly the starting positions of each lockshield before attempting this, there is no harm. This would involve pulling off the lockshield protective cap, and attaching a wee paper flag or similar to the spindle as a pointer. You then close off the valve - turning it clockwise - whilst counting the exact number of turns and part-turns this takes before it stops. Write that figure down on the paper flag, and you can always return to it.

In general, tho', I think there are some other things that can be said. If the rad in question becomes 'hot', as hot as other rads, but its middle-bottom remains cold or cool, then there is almost certainly still some sludge in there. It is perfectly normal for a rad to be cooler as you go towards the bottom, but not 'cold' or very cool. It's usually pretty obvious when it's due to sludge as you can really feel the temp difference - the sludge will prevent the hot water getting to that part, so the only warmth in the outer rad skin at that point will be a bit of conduction from the rest of the rad. It would have been good if the GS had removed the rad and ensured it was completely clean, but hey.

Having said that, if the rad is otherwise 'hot', then clearing this last bit of sludge is unlikely to be transformative.

The use of microbore - although more prone to becoming blocked due to sludge (which this system seemingly had) is no excuse. Microbore should be able to handle the required heat flow.

The room stat needs always to be set higher than its room's temp or else the boiler will go off. What is this other - roomstat - downstairs room used for? If it isn't being used, then turn the rad in there right down as you'll simply be wasting heat.

What about the upstairs rooms - are they bedrooms? If so, I presume they are all turned off/down when not in use? What difference does this make to the downstairs room you are struggling to heat? Any change? If 'yes - it's much hotter', then the bedrooms are clearly pinching too much heat, and that would suggest the rads need balancing, but the simplest solution is obviously to turn off the bedrooms when not in use (and by 'use', I mean a half-hour before bed, and a half-hour before getting up!)

If 'no - the downstairs rads are hot anyway, so turning off the bedrooms makes little extra difference', then it would seem as tho' the downstairs rads are actually working pretty much as intended, but the house is just a harder one to heat. (Provided the two rads are getting nicely hot - if they are not, then perhaps you could try a half-turn opening of their lockshields).

Are there TRVs on all these rads? If so, what are they set at?

Ok, I'm going to guess that the system is actually working 'ok' - or pretty much as well as it ever did - but the issue is that it's an older property with a more poorly-insulated solid 'fabric', and it just needs more prolonged heat to warm up its shell and keep it there. Ie, unlike a modern, well-insulated, house, you cannot just walk in, turn on the heating, and expect to be warm a half-hour later. Like my 1930s house, it takes a good couple of hours to raise its temp, but it stays there quite nicely once reached.

So:

1) Turn off/down any rad in a room that's not being used.

2) Turn the rads and heating on a bit earlier in the rooms you want to 'live' in.

3) Tweak the lockshields of the two rads in that main room open (anticlockwise) a half-turn if you think the rads are being starved of heat - are not 'piping' as other rads. You can always close them off the same amount if it makes no difference. Remember, 'flag' them.

4) Use the electric heater if it's an oil-filled type with a thermostat - oil-filled types have a more steady output. Use it as a booster in order to assist the room to get up to temp, but let the boiler rads do the bulk of the work. Ie, if the room is at, say, 18oC and you want it at 20oC, then have the boiler running for a good while - an hour or more - before you want the room at the 20oC, and turn on the oil-filled rad, say, an hour before too. Adjust the thermostat on the oil-filled until it 'clicks' - that's the current room temp - and then up a further part-turn to roughly correspond to the required temp of ~20oC or so. The oil-filled will now help the room get up to the required temp, and should then turn off. You'll soon work out what the therm' setting on it is for that required room temp - mark it, or note it down. Once the room is at its required temp, turn the oil-fired off, and hopefully the boiler rads will maintain that temp. Ie, use the electric rad only for assisting the boiler to get the room comfy, and turn it off when you can. Hopefully it'll only be running for, say, an hour or so tops.
Even if you need to keep the oil-filled running to maintain a good temp, set its thermostat at that level, so it isn't constantly on. Let the gas do the bulk of the heating. Turn off all unwanted rads.

The plumber did remove the rad and flush it through, added chemicals and also came back couple weeks later to flush it again to check there was no more sludge building which there wasn't.

The rad is cooler, not cold, at the bottom. The plumber couldn't rule out the possibility of some unmoved sludge at the bottom but similar to your comments, due to the heat emitting from the top, unlikely to make any change.

The upstairs rads make no difference to the downstairs. They have TRVs and I've experimented with lowering upstairs. They're on max downstairs.

propertyrental

Is that rad the furthers from the boiler? Long pipe run?

Can you turn the pump up? My pump has 3 settings. Most of the time I use the mid setting (2) but when it's very cold switching it to 3 helps.

jennifernil

Have you checked whether the radiators are sufficiently large enough to be able to heat the rooms?

You can look up the type and size of rad to see the possible output, then compare it with what is required.

Not sure where you can find that, but there must be somewhere.

My OH used to work for a HVAC engineering firm, in their  Civil Engineering department, he wrote a computer program which sized radiators, which he used when we built our house 34 years back.  House heats to required temps within 1 hour

ThisIsWeird

Wrake said:

ThisIsWeird said:

Wrake said:

Sorry the radiator itself. Room just doesn't get warm using the 2 fixed radiators.

I haven't checked the temperature. The other downstairs room (where the thermostat is) struggles to get to 19 and the other room is colder. With the electric heaters I'm unsure of the temperature but I'm fairly confident it would be above 21.

I believe the central heating is working as intended and it is just down to poor design.

The last thing I want is to start making a nuisance of myself but I wanted to make sure there was nothing obvious that the LL had been neglecting in their duties - essentially is it the house's fault, not the LL's?

I wouldn't start trying to balance radiators - you can get yourself tied up in knots, and it isn't for you to do in any case. But, provided you mark exactly the starting positions of each lockshield before attempting this, there is no harm. This would involve pulling off the lockshield protective cap, and attaching a wee paper flag or similar to the spindle as a pointer. You then close off the valve - turning it clockwise - whilst counting the exact number of turns and part-turns this takes before it stops. Write that figure down on the paper flag, and you can always return to it.

In general, tho', I think there are some other things that can be said. If the rad in question becomes 'hot', as hot as other rads, but its middle-bottom remains cold or cool, then there is almost certainly still some sludge in there. It is perfectly normal for a rad to be cooler as you go towards the bottom, but not 'cold' or very cool. It's usually pretty obvious when it's due to sludge as you can really feel the temp difference - the sludge will prevent the hot water getting to that part, so the only warmth in the outer rad skin at that point will be a bit of conduction from the rest of the rad. It would have been good if the GS had removed the rad and ensured it was completely clean, but hey.

Having said that, if the rad is otherwise 'hot', then clearing this last bit of sludge is unlikely to be transformative.

The use of microbore - although more prone to becoming blocked due to sludge (which this system seemingly had) is no excuse. Microbore should be able to handle the required heat flow.

The room stat needs always to be set higher than its room's temp or else the boiler will go off. What is this other - roomstat - downstairs room used for? If it isn't being used, then turn the rad in there right down as you'll simply be wasting heat.

What about the upstairs rooms - are they bedrooms? If so, I presume they are all turned off/down when not in use? What difference does this make to the downstairs room you are struggling to heat? Any change? If 'yes - it's much hotter', then the bedrooms are clearly pinching too much heat, and that would suggest the rads need balancing, but the simplest solution is obviously to turn off the bedrooms when not in use (and by 'use', I mean a half-hour before bed, and a half-hour before getting up!)

If 'no - the downstairs rads are hot anyway, so turning off the bedrooms makes little extra difference', then it would seem as tho' the downstairs rads are actually working pretty much as intended, but the house is just a harder one to heat. (Provided the two rads are getting nicely hot - if they are not, then perhaps you could try a half-turn opening of their lockshields).

Are there TRVs on all these rads? If so, what are they set at?

Ok, I'm going to guess that the system is actually working 'ok' - or pretty much as well as it ever did - but the issue is that it's an older property with a more poorly-insulated solid 'fabric', and it just needs more prolonged heat to warm up its shell and keep it there. Ie, unlike a modern, well-insulated, house, you cannot just walk in, turn on the heating, and expect to be warm a half-hour later. Like my 1930s house, it takes a good couple of hours to raise its temp, but it stays there quite nicely once reached.

So:

1) Turn off/down any rad in a room that's not being used.

2) Turn the rads and heating on a bit earlier in the rooms you want to 'live' in.

3) Tweak the lockshields of the two rads in that main room open (anticlockwise) a half-turn if you think the rads are being starved of heat - are not 'piping' as other rads. You can always close them off the same amount if it makes no difference. Remember, 'flag' them.

4) Use the electric heater if it's an oil-filled type with a thermostat - oil-filled types have a more steady output. Use it as a booster in order to assist the room to get up to temp, but let the boiler rads do the bulk of the work. Ie, if the room is at, say, 18oC and you want it at 20oC, then have the boiler running for a good while - an hour or more - before you want the room at the 20oC, and turn on the oil-filled rad, say, an hour before too. Adjust the thermostat on the oil-filled until it 'clicks' - that's the current room temp - and then up a further part-turn to roughly correspond to the required temp of ~20oC or so. The oil-filled will now help the room get up to the required temp, and should then turn off. You'll soon work out what the therm' setting on it is for that required room temp - mark it, or note it down. Once the room is at its required temp, turn the oil-fired off, and hopefully the boiler rads will maintain that temp. Ie, use the electric rad only for assisting the boiler to get the room comfy, and turn it off when you can. Hopefully it'll only be running for, say, an hour or so tops.
Even if you need to keep the oil-filled running to maintain a good temp, set its thermostat at that level, so it isn't constantly on. Let the gas do the bulk of the heating. Turn off all unwanted rads.

The plumber did remove the rad and flush it through, added chemicals and also came back couple weeks later to flush it again to check there was no more sludge building which there wasn't.

The rad is cooler, not cold, at the bottom. The plumber couldn't rule out the possibility of some unmoved sludge at the bottom but similar to your comments, due to the heat emitting from the top, unlikely to make any change.

The upstairs rads make no difference to the downstairs. They have TRVs and I've experimented with lowering upstairs. They're on max downstairs.

AfaIu, two reasons why a radiator can be significantly cooler at the bottom compared to its top - one is that is has sludge there, but that seems unlikely given what you've said, and the other is an inadequate flow to that rad, so pipes partially blocked, lockshield valve shut right down, etc. 

If the plumber - knowing that there was some sludge in the system - had fitted a magnetic filter and added a dose of long-term system cleaner, then good chance the latter potential cause would be slowly resolved.

It's interesting - tho' I'm not sure how - that turning off other rads haven't improved the temp in this rad much.

It's been asked, I think, but what does the top of the rad feel like - how 'ouch' hot is it?