BALENCING QUESTION

[Balenza]

DP wrote

I would suggest installing a valve on the cylinder return pipe as it is causing the imbalance.

So if the OP,s two radiators which are not heating up properly have a high resistance then this fixed balancing valve will have to be closed fairly tight in order to acheive a flow through them.

I only say this because the lockshield valve on my radiator closest to the boiler is turned on by about a 1/4 turn in order for it not to short circuit the flow to the rest of the system . Its also before any zone valves and when I operate it alone the by pass kicks in returning high temperature water back to the boiler.

If I tried to balance the system as if the hot water circuit is a radiator in order to acheive flow to the CH circuit then on HW only a dribble would be passing through the coil because of the fixed balancing valve and the by pass will be operating just as it does when I have my single radiator turned on.
I find my cylinder of water re-heats in about 25 minutes with no boiler cycling which is not a very long time and a few of rads closest to the boiler warm up when HW and CH on simontaneously. The HW valve then closes and the CH heats up as normal.

 

[Dan Robinson]

Sounds like an unecessary compromise to me but then I don't have such worries

 

[Agile]

If the radiators are heating evenly, each one has the correct temperature difference between flow and return pipes, I would suggest installing a valve on the cylinder return pipe as it is causing the imbalance.

Yes Danny, but we know that the rads are NOT balanced because faced with less head when the HW circuit opens the shortcomings in the heating flow displays itself as little flow in two rads.

I say balance the heating properly as I have explained as a 10 minute job and then it will almost certainly work properly when the HW is on.

Tony

 

[DP]

Tony, you can balance the rads all you want and still have circulation problems IF the cylinder is next to the pump and is plumbed in 22 (as it should be).

 

[Onetap]

Yes Danny, but we know that the rads are NOT balanced because faced with less head when the HW circuit opens the shortcomings in the heating flow displays itself as little flow in two rads.

I say balance the heating properly as I have explained as a 10 minute job and then it will almost certainly work properly when the HW is on.

Tony

Yes the heating does need balancing , but the whole heating circuit is being starved by the HWS demand.
You have to make a compromise between;
a) HW priority but ineffective heating when there's a heating demand
and b) reduced circulation through the cylinder when there's no heating demand, caused by the balancing valve.

My experience is that the balancing valve is usually needed.
You can always leave it fully open if you decide it's not needed.

 

[Dan Robinson]

Though I went through all this 3 days ago... ce la vie.