Cold in the attic.

trailingspouse

I have a 4 - storey house. The combi boiler is in the basement.



I now have a lodger, who lives in the attic rooms. He only moved in in August, so this has only become an issue as the weather has started to get colder - his radiators just aren't quite warm enough. They don't need bleeding.



If I turn the heating up, the downstairs rooms are sweltering but the attic still doesn't improve much.



If I turned some of the downstairs radiators off completely (eg dining room, unused spare room and my bedroom) would that mean the attic rads would get hotter? Or would the house overall just feel colder?

Doozergirl

What's the insulation situation in your loft?

Warm air rises so it should be fairly warm in October with the heat of the three floors below - if you have decent insulation. If you don't, it'll be cold!

Given that the radiators aren't warm enough up there, you may well need to balance the system so that the radiators furthest from the boiler are getting a decent share of the heat.

neilmcl

What is the output of the boiler, is it big enough for your house? As above though it's probably a case of simply balancing the system properly.

trailingspouse

You're right neilmcl the boiler isn't quite big enough (it's a 24, should be 36 I believe for the size of the house - but it was put in by the previous owners and it's never been an issue until now).


Tell me more about getting the system balanced - is that something I can do or do I need a plumber? The system is serviced regularly (has to be, to get my gas certificate). It was last done in May - no mention of any balancing being needed, but maybe they don't cover that in the service?

lindens

individual thermostats on radiators? turn up the ones in the attic, turn down the ones in the ground floor

Doozergirl

Balancing the radiators isn't part of a service. The engineer would just assume that they are already balanced.

The purpose is to regulate the flow of water through each radiator to ensure an even balance of heat coming out of each one. If you have the first radiators with lots of flow they will be really hot and the heat travelling surface area of those radiators dissipates as it travels through the system. By the time you get to the furthest radiators on the system, there isn't enough hot water to heat the rooms adequately.

The size of a boiler is more about hot water demand than heat, so the boiler should pump out enough heat.

You didn't answer my question about insulation.

getmore4less

I would start with the simple test.

turn off radiators and see if the up stairs get hotter.

There is also the possibility the pump does not have the head.

Make and model of the pump?

Mutton_Geoff

trailingspouse wrote: »

Tell me more about getting the system balanced - is that something I can do or do I need a plumber?

Balancing is not part of the service, it's quite time consuming but you can do it yourself ..


https://www.youtube.com/watch?v=QUWbxccVDpc

neilmcl

getmore4less wrote: »

I would start with the simple test.

turn off radiators and see if the up stairs get hotter.

There is also the possibility the pump does not have the head.

Make and model of the pump?

To clarify, don't simply turn off the rads via the TRV, close the lockshields on each, except the one in the loft. Make a note of how much you have to turn the lockshield on each radiator. Also, ensure your boiler has adequate pressure.

southcoastrgi

24kw is more than enough for your heating

akira181

trailingspouse wrote: »

I have a 4 - storey house. The combi boiler is in the basement.

If I turn the heating up, the downstairs rooms are sweltering but the attic still doesn't improve much.

If I turned some of the downstairs radiators off completely (eg dining room, unused spare room and my bedroom) would that mean the attic rads would get hotter? Or would the house overall just feel colder?

Balancing commercial and domestic heating systems used to be my job and radiators take a while to dial in fully. Your combi might be slightly on the small side (you didn't say how many rads total you have) but a decent brand 24kW boiler should be capable of heating all the rads evenly.

Heating works by circulating hot water from the boiler, through the radiator and back to the boiler. Water will always take the path of least resistance, so in this case, it will flow through the radiators closest to the boiler, then return to the boiler, leaving little circulation for the radiators in the attic. This is why downstairs is sweltering and the attic doesn't improve much, the downstairs rads are stealing all the flow.

There's a TRV on one side of the radiator (the big thermostat you use to control the heat) and a lockshield on the other side (used to control flow). On the radiators closest to the boiler, fully close the lockshield and then open a quarter turn. That will restrict flow to the closest rads and push water to the furthest. Then it's just a case of fine tuning all the rads over time until they heat up evenly.