Central Heating. Opening up LSV?

[asalcedo]

One of the rooms in my house does not get warm enough. It has two larg

windows and one radiator under each window.

None of the rooms in the rest of the house has this problem, they al get nice and warm, probably because they are less exposed.

I have drained the radiators in the problem room and opened the TRVs t the max but still it does not get warmer than 20 degrees in these col days.

Perhaps the radiators are underdimensioned for this room.

Or perhaps I can open up the lock shield valves a bit more. Is thi safe or will the whole house central heating get out of balance?

Thanks,

Antoni

-- asalcedo

[asalcedo]

I meant "I have bled the radiators

-- asalcedo

[asalcedo]

No luck.

I tried to open up the LSVs to the max but they were already full open.

Will putting one of those cleaning products through the drain coc help

-- asalcedo

[John Cartmell]

As it's at its coldest when the days are short is it worth-while just concentrating on having insulated curtains/blinds? Wooden venetian blinds in our conservatory seem to work quite satisfactorily to improve the situation.

[Set Square]

OK, so the *room* isn't hot enough - but are the *radiators* as hot as those in other rooms? If they are, then there's not a lot you can do without fitting radiators with a higher heat output - maybe the same size but with fins on the back.

If the radiators are cooler than those in other rooms, balancing may help. If the lockshields in the room in question are fully open, you will have to turn down the lockshields in some of the other rooms - possibly coupled with increasing the pump speed. See the balancing FAQ at

[Ed Sirett]

boiler on it's highest setting, until the weather becomes milder.

[Pachiderm]

If the TRVs are open and the radiators have been bled, they are delivering their maximum output: unless silted up. You'll need to increase their output, either by removing the silt, or by changing them to a higher output.

[Set Square]

Not necessarily! If the system hasn't been balanced, *other* radiators may be getting more than their fair share of the flow, and starving these particular radiators of heat. This is why I asked earlier whether these rads are getting properly hot.

If the rads *are* hot - say 80 in, 70 out - and the room is *still* cold, then - and only then - it might be necessary to fit rads with a higher output.

[asalcedo]

Your point is well taken. Thanks.

One of the radiators is not getting as hot as the others. It is a smal difference and I cannot measure it precisely because I do not have th appropriate thermometer but I feel it.

I will mark the present LSVs positions in the radiators nearby in room that are warm enough and will close a bit those LSVs and see wha happens. Will this risk unbalancing the whole house

-- asalcedo

[asalcedo]

Concerning silt, are these additives, like Sentinel X200 and X100 an good or is there a better way to remove the silt.

I do have bled some radiators where plenty of black water came out.

Thanks,

Antoni

-- asalcedo

[Set Square]

Try to find the hottest radiators, and turn the lockshields on them down a bit. Throttling radiators elsewhere in the house a bit will force more water through the cooler one - the throttled ones don't have to be in nearby rooms. The whole house has probably never been balanced - so there's little risk of un-balancing it!

[asalcedo]

I'll do that. Thanks.

One further question. Once balanced does the system get out of balanc after time?

The previous owner of the house once mentioned that the system wa balanced some years ago

-- asalcedo

[Set Square]

It can do. The most likely cause is that someone disturbs the system - maybe removes some radiators while decorating - and doesn't put it back exactly as it was. Silt collecting in the valves can also have an effect.