2 rads not working

[marsaday]

I have a big system on a house i rent out - 14 rads.

2 rads never get warm and the valves are fully open (the ones which change the amount of water into the rad.

I think it is something to do with the size of the house as it is very big over 4 stories and i had to fit an extra pump on the system when installed.

any ideas ?

 

[Gray0689]

What size pump you got on

 

[oldplumber]

try balancing the whole system before worrying about pumps

 

[Gray0689]

try balancing the whole system before worrying about pumps

It's a 4 storey house so I think the pump size is an issue oldplumber

 

[oldplumber]

how would you know unless you try balancing the system first, after all thats the cheapest option to do first isnt it, one would assume the pumps are ok on an older system after all. I recently changed a boiler in a school where half the rads had never worked, all that needed to be done was balance the system and all worked ok, and the pumps were the same output in the old and new boilers. Got a nicee bonus from the owners as all the previous plumbers had renewed the pumps 3 times and changed the pump sizes to no effect, so in the end it was simply back to basics and I got 3 working hardly used pumps, simpleees, or are you like the plumbers that preceded me?

 

[Gray0689]

how would you know unless you try balancing the system first, after all thats the cheapest option to do first isnt it, one would assume the pumps are ok on an older system after all. I recently changed a boiler in a school where half the rads had never worked, all that needed to be done was balance the system and all worked ok, and the pumps were the same output in the old and new boilers. Got a nicee bonus from the owners as all the previous plumbers had renewed the pumps 3 times and changed the pump sizes to no effect, so in the end it was simply back to basics and I got 3 working hardly used pumps, simpleees, or are you like the plumbers that preceded me?

Read my post I asked what size was the pump!!!!!

 

[marsaday]

the potterton performa 28 has its own pump and we added the same grund pump again. Not sure of their sizes though.

If it is a balancing problem, how do i actually balance it up. Do i shut down rads near to the boiler a bit.

Initially i had a problem with the basement rads not coming on and the pump sorted this. the boiler is in the basement so i think the system is pumping up to the top of the house and then back down again.

 

[oldplumber]

close down the lockshield valves nearest to the boiler and have the ones further away the most, note the ones near the boiler only need to be cracked open normally. you are trying to prevent the flow going around the rads nearest the boiler and starving those furthest away in simple terms. remember to leave the trv/manaul valves fully open on the opposite sides of the rads

 

[Billy Bob Bob]

while old plumber is disappearing up his own arse he does have a very valid point try the balancing first, he is spot on it may be all it takes we know a 28 kw performa will have a 6 metre head,and if you have an additional 6 mtr thats a 12 mtr pumping head i would try balancing first before condemning the pumps report back to us if you dont mind with your findings

 

[GasmanxxxR1]

Turn off all the other rads and see if they heat up, then balance system from there

 

[russblade]

worked for me ! 2 cold rads for 3 months till i read old plumbers and your post, cheers russblade