Central heating system won't play fair!

[a12tfp]

Here’s a problem for all you problem solvers!

I have central heating that’s a sealed system, a 2 way valve (?) with a timer upstairs in the airing cupboard which is also where the hot water tank and expansion cylinder are sited. Downstairs in the hall there’s a Drayton Digistat3 controller. The boiler’s in the kitchen.

We get hot water, so the boiler would, on that evidence alone, seem to be OK.

There was air in the downstairs 3x rad’s 4 days ago (which is when we noticed the fact that the house was cold so bled them then!) but the upstairs rads were hot.
After bleeding them I added more water to the system so it’s now at 1.8 Bar, up from 0.5 (presumably when I bled the rads, I let out too much water!).

Last night the upstairs rads were hot for a 30 minute period. Then nothing. The downstairs rads did not heat up at all.
I’ve played with the Digistat and checked all the settings. Likewise the timer in the airing cupboard is fine too, for all 7 days and the time / date both correlate.
When I ask for say, 23 degrees, we get the flame symbol on the Digistat, but the boiler does nothing.
I’ve spoken nicely to her, but she won’t work.

The system was here when I moved in 7yrs ago.

Any words of wisdom would be most appreciated.
Thanks

 

[kevindgas]

make sure you have the right valve indentified as a mid position valve has 1 in and 2 out pipes whereas a zone valve only has 1 in 1 out

if they are honeywell or acl/drayton there is a lever on the end this should be hard to move and springs back when you let go if the central heating is off. when c/h is on it should be loose and move freely and not spring back.

 

[kevplumb]

View media item 11149 x 1

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[kevindgas]

oooohhh pretty pictures!!

now you know what to look for!

 

[a12tfp]

Good stuff. I'll go and have a look.
Thanks

 

[a12tfp]

Yes!
It's not giving any resistance and moves left - right freely with the c/h off.
Do I buy some Viagra to assist the valve or do I replace it in its entirety?

 

[kevindgas]

Yes!
It's not giving any resistance and moves left - right freely with the c/h off.
Do I buy some Viagra to assist the valve or do I replace it in its entirety?

the honeywell ones can have the motor replaced, the newer ACL/drayton you unclip the head, the potterton/myson ones are screwed on and you replace all the head
the older ACL replace the whole valve and fit a new ACL one.

as a job we charge £80 for the motor change £100 for a head replacement or £175 for the whole body change. others will charge their own rates.

 

[a12tfp]

Sadly it's an ACL, so I guess we're looking at what, draining the system and replacing the whole unit?

 

[a12tfp]

I may have done this incorrectly.
On further inspection, and this is with both the c/h on & off, the arm does move back under a spring (?) tension but it's everso slight and the same amount , be it on or off.

It's an ACL Lifestyle - I have some pictures if it'd help.

 

[a12tfp]

Well, we seem to have heat!
In all the rads.
I had fiddled with the arm on the valve as you'll be aware from the previous postings, but also, I'd read about returning the Digistat back to its original factory settings on this forum.

So, whatever did the trick, it's worked & we now have a warm home again.

I thank you for your advice and expertise.

 

[kevindgas]

depower the system and then manually open the valve a few times as it sounds like the ball may have stuck (probably as a result of summer and not using the C/H) then everything should work properly

the ACL valves come in two designs the fixed one and the detachable one.
on the newer design the head can be detached by pressing the button on the opposite side to the indicator finger and lifting it off
this allows you to move the spindle manually if it sticks.

 

[a12tfp]

Would you credit it?!
Everything was fine for maybe an hour, then off it went!
I've had a wiggle of the arm and notice there's a second small black slider arm (?) on one side of the unit. It's got 3x letters, M, W and not sure what else, even if that's accurate, as it's almost flush up against the hot water tank & I can't really see what it might be or read.
Thanks