what size circulating pump ?

[baldyman68]

Hello,
Newbie question
We have a victorian house of 3 floors & basement.With 11 rads of varying sizes.
The top floor rads dont get hot and we think it maybe the 15-50 grundfos not pushing the water well enough ? even with all the other rads turned off it still dont get up there.
we had a power flush done last year which seemed to help( but then it should of at a cost of £600 ?) but now were back to square one or what seems worse ?
The circ pump is in the basement by the boiler.
Can we have some good advise as to what size would be more appropriate.Before we get ripped off again ?

Many thanks !!

 

[kitch0978]

even with all other rads turned off does any of pipework on top floor get hot? when was last time they all worked....? if at all.......?

 

[kevplumb]

should do it

 

[buck51]

where in relation to your rads on top floor is the F&E tank? if you have one

 

[jackthom]

Is it a closed system or vented with a header tank?



(Wow kev, that's a big one.)

 

[kevindgas]

25/55 should do it but a 25/80 would be better a 15/50 really shouldn't be expected to do 3 floors. a 15/60 might just cope if the rads are small and no more than 15 fitted
These are rough ideas as not seen the house but they are what i would normally use in a similar property.

can you power flush as well with that one kev?

 

[baldyman68]

Sorry all should have added this info too?
3 floors above ground have a ceiling height of 2.74m
basment is 2.5m
Making a head od around 10.22 m I guess ?
F & E tank is in attic sitting on the joists.

It has been some while since the top rads worked or got warm. but have worked in the past.

 

[kev25v6]

Have you checked that the tank in the loft is full of water? I found this to be a problem on an old system when a property surveyor went into the roof and for some reason he turned off the supply to it, found out a week or two later when the boiler started to bang.

 

[picasso]

is there a bypass fitted to the system ?

 

[baldyman68]

F & E Tank full , no by pass ,assume one of the bathroom rads is being used for this ?

 

[JayJay1978]

As a curious DIY'er, what does 15/50, 15/60 mean?

 

[kevplumb]

pump head / inlet size