New trv advice please

[JohnD]

there was no sludge in the system when it was drained. Clean as a whistle.

That's wonderful if true.

But do you mean there was no sediment in the water that came out, or do you mean there is no sediment sitting in the bottom of your radiators and lining your pipes and pump? It's not the same thing.

 

[marb]

Well all the rads work fine now so if there was any sediment it would surely be sitting somewhere wouldn't it ? When we had the boiler installed it was pumped through with a high velocity flush for quite some time which cleaned out a lot of sediment.

What I can't understand at the moment is why the rads are coming on set just above frost, almost at 1. The house isn't that cold, well above 13 degrees max (for setting 1) Perhaps the lockshield valves need to be turned down ?

 

[D_Hailsham]

all the rads work fine now

Do you just mean that they all get hot?

What I can't understand at the moment is why the rads are coming on set just above frost, almost at 1. The house isn't that cold, well above 13 degrees max (for setting 1) Perhaps the lockshield valves need to be turned down?

Quite possible; it's called balancing - that 'dark art'!

If you want full instructions read How to balance a CH system.

However, here's a simple way which will achieve 90% of a detailed balance:

Turn boiler off

Remove all TRV heads

Check that the pin on each TRV will go down easily when pressed and pop up when released. If any are still a slight amount of silicon lubricant should help.

Open fully the wheel valve on other rads.

Remove cap from all lockshield valves

Close all lockshield valves (clockwise looking down)

Open all LS valves by half a turn

Start boiler and wait to warm up

Check, by feeling, the temperature of the return (cooler) pipe of each rad (The LS valve is normally connected to the cooler pipe, but it doesn't matter if it's not.)

Check all rads before making any adjustments, you will then know which returns are hotter/cooler than the others.

Choose one as a 'reference' where the temperature is approximately in the middle of the range

The aim of the exercise is to get the same return temperature on all radiators as on the reference. This is done by adjusting the LS valve.

Turn the LS valve clockwise (close) to reduce the return temperature; turn anticlockwise (open) to increase return temperature. Only adjust by an eighth of a turn, or less, at a time.

You should adjust one valve at a time and wait 5-10 minutes before checking the effect it has made.

You will find that the return temperature of the 'reference rad' will change as you make the adjustment, so you may have to go round all rads several times.

Don't aim for perfection! Provided all rads have approximately the same return temperature and are giving off a sensible amount of heat (feel the middle of the rad to compare), that's good enough.

It's probably a good idea to keep a record of the adjustments you made.

Replace all TRV heads and set to the required temperature.

Set wheel valves to give the required amount of heat from that rad.

 

[marb]

That's great thanks. I will do that.

Cheers.