2 Channel Programmer and customer from hell !!!!

[Theorysparky]

I took a job off my mate the other evening,,wish i hadnt !!!!

85 year old engineer wanted to replace his single channel programmer and put a 2 chan in

well he got in a muddle with his wiring hence the call

it looked straight forward so went up to the immersion heater and notice its a 3 port Y plan system

odd i thought house about 30 years old should have a 2 chan in anyway (alarm bells didnt ring)

took face plate off a 2 gang box to find its wired for single chan......

single chan back on back the next day

rip it to bits and start again for a 2 chan

test the programmer

hot water fine

heating was fine for a while then stopped working when selected

wiring must be fine but double checked

took the heating wire to the valve and put it in the cylinder stat output

works fine

put it back and call for heat

240v into valve nothing out on the orange

disconnect orange 60v ??

reconnect output on orange nothing 0v

scratching my head call my plumber and thinks it may be valve

swap it same fault

the old boy is puling his hair out as to why it isnt working.....he went off on one,,,,,,,,his wife calls the son

explain to him and suggest there was a fault initially on the build which the couldnt be bothered to find so put in a single chan.

what do you want me to do now revert to single chan or fault find from scratch ???

put it back to single channel on the new programmer

gave it one more go before removing cylinder stat and works fine for about 5 mins

then the heating stops calling

now from this i am of the thinking something is breaking down any ideas

pump /stats/valve all ok

only thing i didnt do was use a heating wiring centre as he didnt want the extra cost !!!! wish i had forced it on him

as it stands ive been paid to date he (being an engineer) is drawing his own circuit diagram and may get me back next week

he is one of the guys who wants to help all the time pain

any thoughts guys ???

 

[wooly]

I've had the same problem before. Have you got anything connected to hot water off in the programmer?

 

[Theorysparky]

yep i have

 

[wooly]

So the heating comes on for a while then goes off for no reason? Is it only a problem when the wtr and htg are on together?

 

[Theorysparky]

no

if water is off then selecting the heating the boiler does not start

at one point the boiler would come on but go off within 2 secs

now it doesnt kick in

the only thought i have is there must be a loose/intermittant neutral somewhere on the heating

 

[wooly]

Loose neutral on the valve so it's not pulling it back to mid position/heating position?

 

[Theorysparky]

thats interesting

but why would the hot water then work

could though be a faulty neutral from the wall stat

 

[kme]

Can you temporarily bypass external control inputs mate - see what happens then?

 

[Theorysparky]

did that and it works fine

saying that i did not bypass the programmer

maybe i should link across without the programmer

 

[kme]

No need mate - if it works with the prog. etc. in cct; then they`re proven ok - it MUST be something you bypassed.

Reconnect in sequence, starting with the most likely fault (wall stat?) ; until the fault re-occurs.

( Is the way I`d do it, anyway)

 

[Theorysparky]

what i would like to do is start from scratch and just put the room stat in circuit and work on that

but the old boy wont like that

anyway he has just phoned me up,,,have i got the old wall plate for the old programmer,,,why do you need it ??? just to put it with the programmer FFS

guy is nuts

 

[steptoe]

Do you have a neutral at the room stat?

Some of them can be funny without it.

 

[Theorysparky]

yep i have

tried it with and without snd it made no difference which suggests...

a fault with the wall stat and wiring

thinking about it today it dies when it appears on the orange wire 0v

remove orange from block i get 60v

convinced fault between programmer and motorised valve on the heating cct

whether the old boy accepts this and allows me to test is another issue

 

[lineman]

Was it all okay before the chap fiddled with it? 60v sounds like a dropped neutral to me. Apologies if you have already been through this mate

 

[PC Electrics]

60V on the orange (when disconnected from the wiring centre) is normal if there is 240V signal on one of the grey or white (can't remember which one). Check it out on the Honeywell site - it's a back feed. That's not the source of your problem.

Could there be a pump over-run control on the boiler that is wired in wrong (have found incorrect internal boiler wiring before today).

 

[steptoe]

If the system is running normally and you are getting 230 into the valve then when you disconnect the orange you should be getting 230 on that too,

Did you change the complete valve or just the motor body?

Try disconnecting the valve and wire the connections direct, obviously manually operate the valve to the required position, but that doesnt really matter.

 

[NozSpark]

TBH whenever I get problems like this I disconnect all the wiring, bell it out (if I have to) and then start again (following the manufacturers diagrams)

 

[SPECIAL LOCATION]

60V on the orange (when disconnected from the wiring centre) is normal if there is 240V signal on one of the grey or white (can't remember which one). Check it out on the Honeywell site - it's a back feed. That's not the source of your problem.Could there be a pump over-run control on the boiler that is wired in wrong (have found incorrect internal boiler wiring before today).

Agreed...

The final 230v trigger to boiler has two inputs one from the cylinder stat and one from the orange @ valve.

1)

Water ON: Heating OFF: is 230v from Programmer - Cylinder Stat to boiler.

{valve in home position pulled back by spring} No orange voltage.

2)

Water OFF: Heating ON: is 230v from programmer - room stat - White of valve -internal valve switch - out on orange to boiler.

{valve driven fully over by 230v on white & grey wires}

3)

Water ON: Heating ON: is 230v from Programmer - Cylinder Stat to boiler.

{valve is in the mid position stalled by voltage on white wire through internal diode & resistors}

4)

Water OFF: Heat OFF: 230v will still be going into the valve from the Grey wire.

{No output to boiler, but the position of the valve can be dependent upon its last operate position.}

In condition 3) or 4) the orange if open circuit from other wiring can show 60v - 80v via the internal diode & resistors of the valve.

 

[OnOff]

I have had similar problems over the years. Boiler NOT firing up being the main one. Made the "mistake" of suspecting the synchron motor, replacing it and not fixing the problem. Anyway, on the valve you may see a small PCB with a few components e.g. 2 micro-switches, 2 resistors (one wirewound) and a diode - all easily replaceable. Managed to keep my 3-port 28mm Tower valve going for 13 years and only just replaced it. Just had to make the odd trip to Maplins!

(Was going to post a photo of the PCB on the old one but it seems I've exceeded my upload limit or something......how do I delete them?)

 

[SPECIAL LOCATION]

We had a Honewell 3 port valve operating for 24 years...

never replaced anything on it....

Back on topic...

A quick daft question...

On this heating system has it been drained recently???

any air pockets not fully bled out????

:C