Some intersting quotes from 4xpaws, I swear, I did not read your post first, and when someone mentioned that you had already come up with what I suggested, thats when I went back to check your post, and indeed you came up with same brilliant idea! You've got as good brains as I have!!
Oh Dear Oh Dear
You were never suggesting that it could have been the valve then?
Mike while you are busy patting yourself on the back I think we should wait until the op confirms he has it sorted and while we are waiting I think you should have a recap yourself mate, firstly here is a (edited down) quote from you from when you came into the thread on page 10
when you have a problem on a fairly complex system, it is better to isolate the problem into smaller sections, taking one section at a time, applying logical thinking, one can sort all kinds of hurdles.
But this requires patient and logical thinking.
One also has to have a fairly good knowledge of how central heating systems work, ( etc etc)
Don't forget to rule out the programmer and the timer switch, (etc etc)
By this time, the valve programmer etc had been ruled out, and a few were suspecting the root cause of the boiler shuting down ie circulation problems in ch mode, oh and a domestic heating system is far from complexed btw
you mentioned that the CH only works more or less normally with HW selected, and when CH only is selected it's only on for 30 secs or so.
I'm wondering whether there's a flow problem around the heating circuit, which is being compensated for by the HW circuit when both are selected. It may be that primary flow is increased through the HW circuit as a result of its laboured route around the heating circuit..
About these 28mm pipes, did it used to be gravity primary with pumped heating that been changed to fully pumped?
Is the radiators return pipe goes straight to boiler or via 28mm return? These back boiler use injector tee fitted on gravity return with heating return tee in to help with gravity moving when heating is on.
Maybe the injector is nearly blocked?
Just a thought....
Dan.
reading through I'd say it was definatly a circulation problem on the Rad circuit, the op needs to sort out his pipework
and even before 4xpaws diagnosis on page 9, he suspected
It reads like reverse circulation. Installer's tee'd in cylinder return in the wrong place when converting the system from semigravity to fully pumped and either the CH flow coming off the 3PV is a dead leg, isolated or blocked prior to the first tee on it feeding rads that heat up when the HW is on.
That to me is not an electrical fault, it sounds more like a flow restriction of some sort.
Then you started to apply some logical thought with your brillant Mind
So in my view your problkem appwears to be associated very close to this 3 way valve, on the port that feeds CH flow, but not return,
already ruled out have another Guess
I got a feeling you got something stuck in your diverter valve port to CH
as above
I just had another line of thought, one never knows what happens when one who does not fully well understand the function of things in general, can end up using them incorrectly, or for those who might have a go at things, thinking they are well knowledged about it, but gets it wrong. we know we all love doing things but certain things are best left to the professionals.
Now my new line of thought says,.............
I wont go on as you were wrong But the Quote is absolute class
have another guess
Obviously I cannot rule out yet another unlikely possibility, a 3 way valve internals could be assembled wrongly whereby it will open in two settings and fail to open in a 3rd.
wrong,and the workings of a midposition valve could never be assembled that way, your later drawings used the symbols for a
diverter valve
and any way logical thinking would have told the valve was opening to central heating as the mid position was working fine
then UpgradeME tried to tell you
Mike, one of the reasons this thread is now 12 pages long is several posters are asking the same questions that were discussed and answered in earlier posts.
I can safely assume someone has connected the 3 port valve incorrectly, now that you have determined your flow is fine as you have managed to get all your rads red hot! Time to trace exactly the hot water flow pipe from the boiler to this diverter valve and make sure it is plumbed into the in coming port, usually in the middle, as the middle part
This is a typical example (It's already been discussed, replaced new and if you were to look at the pictures, already know the answer so wouldn't have asked this question...again!)
but you wouldn't listen
I don't know if your comments actually will help Op to narrow down the fault or mine, but still without me reading all 10 posts or so, I am convinced this is his problem,.
His comments were helping, yours were adding to the ops confusion because you couldn't be bothered to read the earlier posts
the valve had been taked out of the equation long ago by people who do this for a living
then more confusion and an early pat on the back
thank you upgradme, that picture clarifies that. pump does indeed feed the port A,
Mind you at first if you don't look more carefully, the angle of the picture taken can easily mislead you with that other pipe sticking from port B upwards in front of the pump. But yes if you exapand the picture you can't miss the fact that the pump is conncetd to port A
But between us all we have somehow got to the bottom of op's problem.
happy ending chaps!
well no it wasn't a happy ending because to everybody else the pump was clearly correctly connected to the AB port and were all trying to figure out the pipework problem for the next few pages
but for some bizzare reason you went back to guessing at the valve (which was I repeat ruled out long ago)
and for a very good video link that explains about a y plan heating systems, the idea is this covers electrical problems since it is quite possible that your 3pv is not sending a live feed to the motor pump when it is in CH mode,
logically thinking not possible at all since the boiler was firing as expected in central heating mode, and an awful video too as his explaination of how it works electrically is totally wrong, as was your possibility concerning the valve,
Doitall is asking Bill whether he traced the pipes with the pump running or without the pump running, I am of the opinion, that he should check with the pump running since that is how the water will be forced to flow, whereas, just relying on gravity it may run or flow in the opposite direction and give us confused results,
Doitall's test was a good logically thought out one, it has been explained to you why
since you couldn't get your brilliant logical brain around it
ps sorry mods for the excessive quoting
Matt
