Changing Radiators....

[ray316]

l have a baxi solo 3 40pfl boiler and 7 radiators around the house. The radiators have been in over 20 years and look tatty now and l think some are gunged up as the water is black when l bleed them and some are cold.l was thinking of replacing some of them.
Some are double radiators, would l have to change like for like.
Do they have to be the same length and height or can l change for smaller or larger radiators and just alter the pipes to fit....

 

[muggles]

You can have whatever size of radiator you like provided the new radiators have the same output as, or better than, the old ones. You can't just randomly put a much smaller one in "because it's in the way" and still expect it to heat the room, because it won't.

 

[ray316]

You can have whatever size of radiator you like provided the new radiators have the same output as, or better than, the old ones. You can't just randomly put a much smaller one in "because it's in the way" and still expect it to heat the room, because it won't.

Muggles you say as long as the new radiators have the same output or better than the old ones...
How can l tell the output for radiators.
Also you say putting a smaller radiator in will not work, would it not still get warm and heat up then...

 

[muggles]

Do your current radiators have fins welded to the back / middle or are they just plain panels? This will make a difference to the output.

A smaller radiator would indeed still get warm and heat up, the issue is that it may turn out to be too small to heat the room adequately; for example, if your room needs 2kw to heat it and your current radiator puts out 2kw that's fine, installing a smaller radiator with a 1.5kw output will result in the room not being adequately heated, IE you will be cold. Or, to look at it another way, you can boil a kettle quite quickly on a gas hob but it would take a lot longer to boil it using a candle, as the candle is less powerful, and in fact the heat lost out of the spout would probably overcome the heating effect of the candle, so that the water would never boil.

It might be worth taking the opportunity to increase the size of the radiators in any case, as larger radiators will be much more efficient should you ever have a condensing boiler installed.

 

[xr4x4]

theres a calculator somewhere for working out what size rads you need.

uses room size, insulation, etc etc.

 

[ray316]

My radiators are either double or singles with fins.
If l have larger radiators will the boiler be ok, would it cope with the increased size on the radiators....

 

[muggles]

Not a clue, you haven't said what size the radiators you already have are