Vaillant ecoTEC 831 with Timerswitch130 and Honeywell DT92E

[Vyker]

Hello,

I have a bit of a problem. I have a Vaillant boiler, which is great. The Timerswitch130 inside the boiler is terrible.

I want to know if I can remove it completely [leaving the fascia exposed] and not replace it, and have the Honeywell control the boiler on its own.

The reason I ask is that to have the Timerswitch130 set to on, ignores anything i do with the Honeywell, the boiler will heat the house nonstop, literally cooking the place.
Leave the Timerswitch130 off, and it ignores the HW again, no matter what temp i set it to and get the little flame icon, the boiler wont react.
Last option for the Timerswitch130 is the timer option, where it uses the analogue dial to set when the boiler should go on, but even then, I don't feel as though it works well [especially as the timing is off, one real world hour is two hours on the timer]

So what I really want to know is, can I run the boiler without a Timerswitch130 at all, and use just the HW to control when the boiler comes on or off.

Once I work that out, I want to replace the HW with the Heat Genius system. This leads to my second question: the Heat Genius HG uses a boiler back-plate, apparently it's a standard back-plate used by most boilers - the HW doesn't have a back plate - where do I get a new back-plate from to install it in preparation for the HG?

Thanks for any help or replies in advance.

Regards

 

[GuessMan]

The problem is in how the HW (Honeywell) room stat has been wired. Either wire 3 on the boiler to A & 4 to B or put a link from L to A & wire B to 3 on the PCB. This is for the original EcoTec; if you have the newer version ignore the first option and using the 2nd one, wire it to RT instead of 3.

You can then remove the timeswitch or leave it in to perform its correct function.

 

[Vyker]

Thanks Guessman

I don't know enough to completely decipher your message, though I appreciate the reply.

The boiler was installed last year in March, so I guess it's a new one.

I'll take some pictures tonight, and post them up with my interpretation of the instructions, if you don't mind checking over what my plan is, it'd help.

 

[GuessMan]

On the receiver box for the Honeywell the terminals are labelled (in order)
N L L A B C

On the original EcoTec PCB
L N Earth 3 4 5

On the new EcoTec
Rt L N Earth

All from memory, so will be about right. Which EcoTec do you have, does it have control knobs, if so it's the original.

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• GuessMan
• 18 May 2015
• 1

This is the first option substitute T1 for 3 & T2 for 4

 

[Vyker]

Here is my current setup.

The Boiler front

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• Vyker
• 18 May 2015
• 1

And the thermostat back plate.

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• Vyker
• 18 May 2015
• 1

It looks like I have some sort of loopback between B and the second L, and from L to L.

No idea how the colours correlate to the letters though, or which colours mean what coming from the boiler.

There is also some cut cables shown here...

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• Vyker
• 18 May 2015
• 1

A green and blue one...

I don't have much confidence in the way this has been setup - any laymans help to solve this would be great.

Really want to get the thermostat working normally, and ridding of the terrible TimerSwitch in the boiler.

Thanks

 

[GuessMan]

OK you have the later EcoTec.

The wiring in the Honeywell receiver looks correct. The wire from B should be going back to RT on the PCB. This is the connection by the green mains plug on the boiler PCB.

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• GuessMan
• 18 May 2015
• 1

Has the 24V room stat link been removed?

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• GuessMan
• 18 May 2015
• 1

The one on the White plug

 

[David937]

On a completely different note, the pressure looks a bit high at 3.1bar!

 

[Vyker]

On a completely different note, the pressure looks a bit high at 3.1bar!

It is, and reaches even higher levels, I just don't know how to reduce it. Boiler service is booked for the 27th, hoping the BG HC guy can solve it for us.

I'm also not savvy enough with changing the wiring, it's not clear to me, so I need to learn a bit more before I can exercise GuessMan's advice.

Can't wait to get rid of that horrid TimerSwitch and use the Honeywell to it's potential.

 

[Gasescape]

Is the Honeywell receiver not wired wrong ?
Both lives & B are linked !!!
Should it not be lives & A linked & switching on B ?

 

[GuessMan]

Is the Honeywell receiver not wired wrong ?
Both lives & B are linked !!!
Should it not be lives & A linked & switching on B ?

well spotted sir

 

[D_Hailsham]

Is the Honeywell receiver not wired wrong ?
Both lives & B are linked !!!
Should it not be lives & A linked & switching on B ?

well spotted sir

There is also no need for the brown wire link between the L's as they are linked together internally. Remove this link

Move the white wire from B to A. (leave the other end in L.)

 

[Vyker]

Thanks very much for your responses chaps - very helpful.

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• Vyker
• 21 May 2015
• 1

Can you double check the changes in the image above?

If I make the changes 1) and 2) above, that will mean I can take out the TimeSwitch and use the honeywell to control when the boiler turns on or off right?

 

[D_Hailsham]

If I make the changes 1) and 2) above, that will mean I can take out the TimeSwitch and use the honeywell to control when the boiler turns on or off right?

You have understood my simple instructions perfectly.

There's no need to take the clock out. Set the switch on the left to 'ON' and the clock will be ignored. The boiler will then be controlled by just the thermostat.

 

[simond]

Am I missing something here?

The DT92RF has no timer and is not a programmable room stat.

So by removing the timer (if I remember correctly you can just prise it off the facia remove the pin link and replace it to cover the hole) you have just a set temperature.

If you want to control times and temps you need a CMT927; or an Evohome Base Unit, or a YT87.

With the latter two you can add internet control and programming, the YT87 only gives timings via the internet app. All use the same relay box (BDR91) you have been struggling with.

 

[Vyker]

Is the Honeywell receiver not wired wrong ?
Both lives & B are linked !!!
Should it not be lives & A linked & switching on B ?

well spotted sir

There is also no need for the brown wire link between the L's as they are linked together internally. Remove this link

Move the white wire from B to A. (leave the other end in L.)

I made these changes, and it didn't work. The boiler wouldn't fire anymore. It almost feels like the boiler is getting its power from that L-B loop. Is that even possible? to have a boiler powered from the boiler control?

The test was - apply changes as suggested here, run up the temp on the wireless stat to trigger boiler command, flame symbol appears. Boiler control lights up its green light, but the boiler does nothing. So I had to revert back to the wiring in the images above to get heating again.

So my next plan is to start fresh and re-wire it all again. I'll buy some HR 3 core cables and start again.

I've bought Hive. Here is what Hive says you should connect.

And here is the circuit diagram for my boiler... the Vaillant EcoTec 831 Combi

Can someone just help me line up Hive's N L 1 2 3 connections with points on the circuit diagram please? At a guess, I'm going to need something on X100? Pink blue and white? and also at X1?

Any thoughts/help/suggestions would be great.

EDIT: What cable thickness do I need, 0.75mm, 1mm, 1.5mm or thicker? Thanks