Fitting new 5111603 PCB to suprima 50

[matt1e]

hi davina

am i missing something or are you trying to diagnose an electrical fault woithout a multi meter

not quite, we are trying to diagnose a HEATING fault woithout a multi meter but I do think there may be the chance of incorrect wiring

stop. you're potentialy going to hurt yourself or someeone else.

How??? if using user controls is dangerous then there really is something wrong with the wiring! neither me or mandate have mentioned anything in regards to doing anything hazardous, this is the sort of advice I'd give my sister over the phone (followed by ok i'll be over tomorrow ) put it this way if one of our engineers phoned me for advice regarding a suspect micro switch and he didn't have a meter first i'd slag him off for not having a meter (my fav tool) but I'd still tell him how to test it with a small piece of wire no such advice has been given here

you also are going to waste money throwing unneccesary parts at the heating system

this was my point! ie based on info given get wiring checked before changing the valve

just payout for someone who knows what they're doing and this'll probly get solve in les than 2 hours

To be honest if it took me longer than 45 mins on site to diagnose a wiring fault on a y-plan then I'd be disappointed

 

[gavinda]

matt1e, i wasnt beign funny but as you said , if one of your engs tried to do that without a meter you;d be a bit miffed. i had an eng calll me all the way across our district as he had a wierd fault with a 3 port valve. hed changed the mid pos and the room stat. all the wiring LOOKED ok. the problem was that the clock had never had a hw of wired into it. the couple had had the boiler changed and the installer had told them how they could have individuall times for hw and ch. neither my eng nor the installer had checked the individual wiring and my eng had plunged in throwing parts at the system. 2 hours he was there for something that wasnt wrong and could have been diagnosed in 15 mins with the righ tools.

so im not having a go just trying to save you some grief.

good luck.

 

[Grindstone]

Hi All,

Really appreciate the help, especially as I have had three plumbers out to this and none of them have resolved it. I'll try the tests you advise tonight Matt when I get back, I've got to say it is sounding motre and more like micro switch 2 that is at fault.

I have a neighbour who is an electrician, (knows nothing about plumbing or boilers), but I'm sure will be proficient with a multi metre if the things Matt advises tonight are inconclusive I'll see if I can get him to test the wiring as per the diagram.

If it is the micro switch I have a replacement actuator, but its the snap on one, not the one that needs the valve as well. Am I right in assuming that I can swap the micro switches from that with the older type, clearly after turning off the power.

 

[MANDATE]

If it is the micro switch I have a replacement actuator, but its the snap on one, not the one that needs the valve as well. Am I right in assuming that I can swap the micro switches from that with the older type, clearly after turning off the power.

I doubt very much if you can swap micro switches. I dismantled a potteron actuator head and the micro switches lay side by side in a compact space and were soldered in.
There are distinct advantages with a new head, cause you get a new motor and both micro switches, so I'd advise changing the valve body.

Also Do note what I said earlier.
When the HW and CH are both switched off, the wire from the HW OFF terminal which is connected to valves 'grey' wire is still 'live', for this reason the power to boiler must be isolated by removing fuse before removing wires.

 

[gavinda]

pretty certian you cant swap those microswitchs otherwise ud be doing that instead of wiring new heads in. that i suppose is why i was so keen on the use of the multi meter in the 1st place .

water only 240v on orange only

water and heating 240v on white and grey

heating only. 240 white grey and orange.


hth

 

[Grindstone]

Ok here we go

CH HW on Cyl stat demand room stat demand switch M boiler on
CH HW on Cyl stat demand room stat no demand switch M boiler on
CH only Cyl stat demand room stat no demand switch H boiler off
CH only Cyl stat demand room stat demand switch H boiler off
HW only Cyl stat demand room stat no demand switch W boiler on
HW only Cyl stat no demand room stat no demand switch W boiler off
CH HW on cyls stat no demand room stat demand switch H boiler off

The only way to get the rads to heat will be to turn the cyl stat up. This will keep the heat on constantly, I guess even when the cyl stat is satisfied, it must do or the house would get cold, and it doesn't.

Does this help?

 

[matt1e]

Hi gavinder
not a problem mate I was up all night with toothache! so maybe twas me having a go at you my apologies and I do share your views regarding electrical fault finding with out a meter as there is only so much you can do
anyway back to the problem Grindstone why didn't you say you had a sparky mate? go and get him and his multimeter it'll take half an hour of his time and he'll gain experience
it will help if you show him the diagram on the previous page

right with hot water only selected at the clock and the cylinder stat calling (turned up) you should have 230v between orange and neutral only
the boiler should also fire

now turn the cylinder stat down- the boiler will go out and now there should be 230v between grey and neutral only

right now turn the cylinder stat back up and go and turn the hw off at the clock you should have exactly the same result as before ie 230v between grey and neutral only

now select central heating only and turn the room stat up there should now be 230v on white ,grey and after a short while orange (the time it takes for the valve to fully open and close the suspect micro switch)the valve will now be at H

now turn down the room stat 230v should now be only on the grey and the valve will stay at H because said voltage is holding it there
now turn the room stat back up and turn the hw back on
now you will have 230 on the white
230 on the orange
and strangely 115-160v or so (depending on the make) on the grey
this is normal and happens when the valve is at mid position due to the resister and diode now being connected to the grey via the first microswitch toggling over at mid position
and also the valve will be now at mid position
THERE WILL ONLY BE 230 ON THE GREY IF THE CYLINDER SAT IS SATIFIED

think of it like this
white live= central heating on valve at m or H
grey live = hot water OFF valve can be W or H
grey = HALF live Valve at MID (halfway)
orange live = boiler is on Valve can be anywhere

If problems are found concerning the orange tell your sparky to select central heating only
AFTER valve is fully open look at the diagram and use the colours avial at the valve use a link and bridge out the bottom micro switch
if boiler fires micro switch in valve head KAPUT
if boiler doesn't fire = continuity wiring fault in cly stat connection 1/orange/boiler switch live common leg

matt

 

[gavinda]

re reading this thread, i feel that the issue may just lie witht the clock. as you have the actuator allready why not wire it in and see how the system reacts.. at least you'll know then.

 

[MANDATE]

water only 240v on orange only

While this statement is true, it should be noted it is due to backfeed from the cylinder stat and not fed through the valves micro switch.

water and heating 240v on white and grey

If valve is in mid position (water and heating both in demand) then 'grey' cannot be 240v.

 

[gavinda]

yeah not sure what i was thinking there, though i do remember feeling cinfuzzled as i typed it.

shame on me.

 

[matt1e]

hi again

CH HW on Cyl stat demand room stat no demand switch M boiler on

not possible with a correctly wired system
there can be no other position but W there should be no voltage on the white or grey

matt

 

[gavinda]

thats what made me suspicious of the clock wiring.

 

[matt1e]

yes and there has been a new clock wired in and a room stat added
anyway you definitely need your wiring checked

 

[Grindstone]

Ok I'll see if I can get the sparky chap around. Re the clock it wasn't re wired, straight replacement for the old clock that just slotted over the hard wired fitting.

Got up this morning and the switch was at H, rads hot, but cooling, thermostat still calling, but the boiler was out, I increased the cylinder stat slightly and the boiler fired, switch moved to M and the rads heated up again.

Anyway I'll see if I can get him to test tonight and then let you know.

Re the actuator, the new one I have is the right one I believe see the earlier posts, but I'm not clear if I can get the old one off, hence the pictures. The one I got is listed as the replacement part for the older model, I only have the head however, not the full valve. Otherwise I agree fitting this may well have removed the actuator as a potential problem.

 

[MANDATE]

Got up this morning and the switch was at H, rads hot, but cooling, thermostat still calling, but the boiler was out, I increased the cylinder stat slightly and the boiler fired, switch moved to M and the rads heated up again.

I think that is understandable. That would be both HW and CH switched on and both in demand. Radiators get hot along with HW, but after HW is satisfied valve would move to H. At this point there were two possabilities.
Either (a)CH came on and become satisfied, so boiler would be out or (b)CH did not come on (due to faulty micro switch) so boiler would be out and CH was not satisfied.
By creating a demand for HW with cylinder stat valve drops back to M (because CH also not satisfied) and rads heat up again.
Had CH been satisfied, valve would have dropped back to W.
This still indicates micro switch promblem!

CH HW on Cyl stat demand room stat no demand switch M boiler on

Agree! with no demand from room stat, how could 'white' wire move/hold valve at M. (Perhaps room stat not wired correct)