Help replacing strangely wired Danfoss 4033

[REFaust]

Hi

Hope someone here can advise.

I wish to replace my broken Danfoss 4033 MKIII with a new controller and have purchased a FP715 replacement.

However when looking at the wiring diagram on the Danfoss website in order to identify the current setup I noticed that mine is not wired as they say it should be.

They say

1 - DHW Com

2 - Htg On

3 - Htg Off

4 - DHW On

5 - DHW off

6 - Live (2 wires, one mains and one to Htg Circuit)

7 - Neutral

8 - Earth

This can be seen in the bottom picture here:

http://www.danfoss-randall.co.uk/Si...ntLevel=1&intSubPage=1&intStepsSincePSearch=2


However, here's the problem. Currently mine is wired as follows:

1 - Linked by wire across to 6 (Live)

2 - Red Wire (presumably Htg On?)

3 - Empty

4 - Yellow (DHW On?)

5 - Blue (DHW Off?)

6 - Incoming Live and wire from 1

7 - 1 x Black (?), 1 x Blue (Neutral)

8 - Earth

My boiler is a 3* 6270, with gravity fed hot water tank above.

Can anyone help identifying why there is a link across form terminal 1 - 6, and/or why there is an extra wire in terminal 7?

Any help greatly appreciated.

Thanks

R E Faust

 

[wilhelm]

are you getting confused about the wiring thats needed to operate the timeswitch itself and thewiring that goes to wiring centre.
ie link 6-1 is reqd for dhw time live
and 7 has another nuetral going to wiring centre/ term strip

?

 

[REFaust]

are you getting confused about the wiring thats needed to operate the timeswitch itself and thewiring that goes to wiring centre.
ie link 6-1 is reqd for dhw time live
and 7 has another nuetral going to wiring centre/ term strip

?

Sorry, I don't understand your question.

The replacement FP715 - which was the one I was recommended by Danfoss technical sales- has only L, N, and four other terminals (H on/off and W on/off) on the mounting plate, which has to be replaced from the one on the 4033. This, as I said, has 8 teminals. One of these is earth and the FP715 is double insulated, so that's one sorted out. My confusion is why there appears to be no wire in terminal 3, which should be HTG off and what to do about the wire from 1-6 since there is no equivalent terminal on the FP715 - I assume I just remove it? If so all I need to do is identify which is Htg off - since its not in term. 3 where the Danfoss guide says it should be.



R E Faust

 

[ChrisR]

Look at the wiring diag you referenced - the link 1 - 6 is just to get power to the common terminal. It's connected internally in your programmer.

You don't normally need a wire in Heating Off
From http://www.danfoss-randall.co.uk/de...ntLang=2|strLang=|intLevel=2|intLevel2ID=1262
it would be term 2 if you did...

 

[simond]

In all honesty, RE Faust, if you are confused by an extra wire in the neutral terminal you are out of your depth and could get in a pickle. However, all credit to you for documenting the cable allocation, this was the best route.

Looking at your initial set up you have a typical system with a three port motorised valve.

The only terminals you need are;

Live - as before
Neutral (use both the black and blue cables as before)

DHW off - Blue
DHW on - Yellow
HW on - red

The link cable is now superfluous because the newer programmer has this fitted internally and can be discarded.

 

[REFaust]

In all honesty, RE Faust, if you are confused by an extra wire in the neutral terminal you are out of your depth and could get in a pickle. However, all credit to you for documenting the cable allocation, this was the best route.

Looking at your initial set up you have a typical system with a three port motorised valve.

The only terminals you need are;

Live - as before
Neutral (use both the black and blue cables as before)

DHW off - Blue
DHW on - Yellow
HW on - red

The link cable is now superfluous because the newer programmer has this fitted internally and can be discarded.

Thanks for replying.

I will follow your guide but I was wondering whether I will be able to have any seperate control of heating with the FP715 without the htg off terminal connected.
I do have some knowledge of electrics as I work in Film/TV lighting - but absolutely none of boilers.

Cheers

R E Faust

 

[simond]

Ah! I used to work in lighting (Presentation and Rock n' roll) too.

Your previous prog would most likely have had 'CH off' on term 3, which you confirm was not connected.

Very few heating system configs use the CH off connection. Don't feel obliged to fill every terminal!

 

[CluelessSteve]

Hi,

I have almost an identical situation as the OP. However my system has nothing in connector 3, but two wires in connector 5.

I assume this is both CH and HW off merged into one.

So, I wired it up using the FP715 wiring conversion chart as supplied, and put both wires into connector 1.

I wonder if the original installation had HW and CH wired in reverse, because now when I switch the HW on the CH comes on (IE: Rads get hot) and switching the CH on causes the pump to start and the little motor valve to whir a bit for a few seconds then it all switches off. Switch the CH off again and the rads get hot (cos HW in new switch is switched on...)

Nothing is ever blooming straight forward is it?

Can some one give me a pointer as to how I definitively identify the wires being for the CH or HW as they enter the wiring block? (Where should they lead to for example)

I am not a CH engineer, but have a good working knowledge of elictics so happy to dig about a bit..

Steve