Whats next ?

[Buffy330]

Hi

my really old large house used to be a real mess in terms of several old heating systems that were cobbled together and extensions to it.
Not to mentions redundant pipework from Back boilers and a Rayburn/Aga style device in the kitchen.

Now - I have the original gravity fed Potterton Kingfisher2 floorstander - and Im happy with this .
22mm flow/return from the boiler to the rest of the system - all new.
Downstairs - I have 22mm feeding 3 radiators off the flow / return.
Upstairs , I now have a new 22mm single run of flow/return with no spurs , just feeds to upstairs radiators and drops to the remaining downstairs radiators.

Total number of radiators is 18 !!!

The system is pumped by a Grundfos UPS 15-60 130 pump.

The only 15mm copper is is from the flow/return to the radiators.

Now I have bought a thermo gun ( Bosch ) to measure the temps of each radiator in order to balance them , but my problem is what seems to be a lack of flow.
At no point does the drop in temp across the flow and return pipes mirror what is acceptable , therefore I am suspecting poor flow.
In fact the return is pretty close to cold !!!

All new pipes , new valves , new radiators and a filter ..... but sometimes when I open a bleed screw , all I get is slight dribble.

Any pointers please ?
The pump is only a couple of years old and I bled that too

Many thanks for reading this

Steve

 

[exedon2]

OK what output is your boiler and what are the heat requirements of your 18 rads?

 

[Buffy330]

OK what output is your boiler and what are the heat requirements of your 18 rads?

As a layman , could you elaborate please and I will endeavour to sort the info out

Thank you

 

[exedon2]

Your boiler will have its output on a data label somewhere,
Measure all you radiators then find there outputs by using rad size list (lots online if you look)

 

[ShaunCorbs]

I’m guessing it’s open vent eg tank in the loft also ?

 

[fronty]

What speed have you got your pump set at? Have you tried it on it's fastest setting?

 

[Buffy330]

Your boiler will have its output on a data label somewhere,
Measure all you radiators then find there outputs by using rad size list (lots online if you look)

I have added up the value of the radiators and it comes to 112609BTU
The picture is from the boiler

 

[Buffy330]

I’m guessing it’s open vent eg tank in the loft also ?

Yes - the tank is in the loft and feeds correctly - no blockage.

 

[Buffy330]

What speed have you got your pump set at? Have you tried it on it's fastest setting?

Speed set to 3 , and the pump is bled and quite new.

I just dont seem to have much flow , and the house is very large , with long pipe runs

A second pump perhaps ?

 

[fronty]

Hmmm, I'm not an expert here, I've got 13 rads, pump speed is on 2, boiler output is 26kw. It could be a combination of not enough flow and an under-sized boiler. Yours is between 23-29kw which feels a bit marginal to me for 18 rads.

How about closing off all your radiators apart from the one at the end, then open the bleed screw and see what comes out, you should get more than a dribble that's for sure, mine hisses and spits and it generally Sodes out when all the air is gone. If you open the lockshield all the way you'll get maximum flow through the rad, that will prove that the pump has enough oooompf to push the water that far. Tighten the lockshield until you get your temperature drop. If that rad gets nice and hot with all the other rads closed then it might be a case of rebalancing them all.

 

[SJB060685]

Sounds to me this is a lack of pump head problem. Are some of the radiators getting hot? ie, those close to the boiler, or none at all?

 

[exedon2]

On the face of it your boiler is undersized I take it it also heats your hot water? If so add 10000 btu.
Is the boiler set at maximum? (Needs a G S R engineer to check.

 

[John.g]

Speed set to 3 , and the pump is bled and quite new.

I just dont seem to have much flow , and the house is very large , with long pipe runs

A second pump perhaps ?

Can you post a picture of your pump?. with exact model details.

 

[Timmy D]

Just throwing this out there. You said it’s all new pipes. Who ran the pipes? Are you sure the 22mm flow/return are not joined at the furthest end?

 

[exedon2]

Looks to me you have a heat load of around 36kW
With a boiler that can do 29kw tops (this is without allowing any sort of margin)
Most of your rads (15) are on a 22mm circuit you seem to be pushing the limits in all directions.
I'm not saying it can't be made to work but you will struggle with current layout.