Cold Rads

[rdo1104]

Hi, hoping you can help!!

Yesterday I removed a downstairs rad to change leaky valves. I drained the system before removing the rad, changed valves, refilled system then bled rads.

I now have cold radiators throughout the house.

I have a pump fed system (Myson pump) with a Honeywell 3 way valve.

Everything is in the loft so is easily accessible.

The pump appears to be working on all 3 speeds, I have hot pipes to and from the cylinder loop so no probs with HW however the pipe leaving the valve as Flow for the Rads is only luke warm for the first 4 - 6 inches and then is cold so it doesn't appear that the water is getting through the valve.

Valve is only about 2 - 3 years old at most and was working perfectly up to removing the rad yesterday (law of sod).

Any ideas??

Thanks

 

[D_Hailsham]

Did you set the Honeywell valve to MAN when you refilled the system?
Have you bled all the rads? (should be done with water cold and pump off)

 

[seco services]

is the valve opening when calling for heating only ?
is the lever on the end of the valve loose with no resistance ?
is their anywhere near the valve that has a vertical pipe with a bleed valve on top so the pipework can be bled

 

[rdo1104]

Thx for prompt responses.

In answer to most of your questions:

I have bled all rads in cold state with system off. Giot air out initially but just water now.

The valve had no resistance however, I went to get another one from the shed and was going to change it over so switched power off and at this time the existing one decided to have some resistance so have set it currently to manual.

I didn't set the valve to maual when refilling - what impact will this have.

There is a vertical feed with a bleed valve on it which I have bled and removed the air so far.

I've also tried to bleed the pump but only a couple of drops of water from there

Just checked valve and it has removed itself from 'manual' and there is no resistance - I'm guessing this is not right?

Thx

 

[seco services]

if the heating is calling then the lever won't have any resistance on it.

 

[seco services]

i would say you have an airlock in your drop down pipework from the loft.
set the pump to max

 

[rdo1104]

Seco

Should I just leave it running to clear the airlock? The CH was on for some time yesterday and never got warm.

Will the airlock move eventually?

Thx

 

[seco services]

no not if it hasn't moved by now.
have you tried stopping the heating so as any air in the drop downs can rise and you can bleed it from the loft bleed valve.
otherwise your just trying to push air down.

 

[rdo1104]

I did bleed it again this afternoon after it had been off for a while and didn't really get any air out.

What is 'Plan B', is there a 'Plan B'.

Would it be easier to drain down the whole system again but with the valve in the MAN position?

Apologies for not mentioning before but it is 15mm upstairs and 10mm microbore downstairs and I drained it from one of the downstairs legs - will this have made any difference?

Thanks Seco

 

[seco services]

so you say the heating pipe comes out the valve andis hot for about 8",
how far does it go horizontal before dropping through the ceiling and vertical down the wall ?

 

[rdo1104]

I'll try and explain as it's not as simple as just dropping straight down. We had the cylinder placed in teh loft and an extension built so here goes, and this may explain a lot:

The pipe exiting the valve is in 22mm copper, it elbows 90 degrees almost immediately and flows horizontal for 6 inches to a T.

The T rises in 15mm for around 10 inches to the bleed valve. In the other direction it drops in 22mm vertically for around 18 inches but then runs horizontally across the loft floor for possibly 8 - 10 metres before dropping again and at one point has a slight incline as the pipes go through what was my old gable end into the new extension loft.

Hope that helps to visualise and I think I can see where you are going now as there is a lot of horizontal.

Would appreciate your thoughts
thx

 

[seco services]

8-10 metres across the floor is a long way horizontal.
i would poss say thats where the airlock is.
and opening the bleed valve for a few secs won't shift the airlock 8m.

is their any compression joints along this 8m length ?

 

[D_Hailsham]

I didn't set the valve to manual when refilling - what impact will this have.

When the valve is in the auto position and the power to the valve is off, only the Hot Water Port (Port B) is open. Locking the lever in the MAN position opens both CH (port A) and HW ports. This allows the water to circulate through the radiators when the system is being refilled.

Just checked valve and it has removed itself from 'manual' and there is no resistance - I'm guessing this is not right?

Turn the power off. This will reset the valve so only port B (HW) is open. When you push the lever across (to open port A) you should feel resistance as you are pushing against a spring. If there is no resistance the valve is stuck. Remove the actuator box and you will see a shaft ticking out of the body opf the valve. This should be fairly easy to turn (it only turns through about 20 degrees). If stiff you may be able to free it using a pair if pliers to turn the shaft.

 

[rdo1104]

unfortunately not. This length is in plastic so a single piece with pushfit elbows where goes to vertical

 

[seco services]

hard to try pic it but i would turn heating off so the valve is closed and try bleeding the vent for a while see if it lets the airlock up.

can you get a bowl or anything to catch the water ?
or slacken the nut on the end of the valve.