Webasto heater wiring

[Dr Bob]

I'm getting cheesed off with my Webasto control thingy giving me little control. Great, you can program it to come on 3 times a day but it never switches off.

 

I'm going to fit a google nest but what wire do I need to connect for the 'request for heating'?

Looking at the 4 wires going into the controller, there is one red, one brown and two black. I assume from looking at wiring diagrams the red is the +ve, the brown the -ve and the blacks then must be the request for heat wires.

I am guessing if I put 12v down the black wire from the google nest, the webasto will fire up.

The guy on the boat next to use wired his up that way but he's not around to work out which wire he used!

[Moke]

Doesn’t the Webasto wiring have a little square plug on the end of it? That should plug into the controller…..at least it did on mine. 

[Dr Bob]

1 minute ago, Moke said:

Doesn’t the Webasto wiring have a little square plug on the end of it? That should plug into the controller…..at least it did on mine. 

Yes, its a little square plug with the 4 wires.

I want to ditch the controller and connect the wire that fires up the webasto to the google nest. Is it the black one?

[Tonka]

[Moke]

That’s the idea as in the picture. 

[robtheplod]

Interesting thread... I suppose it could be made to work with a relay also for those who can remotely control the relay?    is it just short a1 to a2 and bingo or not as easy as that?

[Moke]

To be honest it was dead easy to plug the heatmiser thermostat into the Webasto, it’s plug and play really. I bought a Webasto extension loom so the thermostat could be mounted in the saloon. It got the heating up and running but the thermostats controls were so clunky I just went onto fleabay and bought what’s called the Hub Unit which connects to the router and lets me control the heating system from my phone. It can be set up with 6 times for on/off all at different temperatures, plus you can modify it from anywhere in the world.  Drawbacks……if you’re moored in an internet dead zone you have no control whatsoever, even if you’re sat two feet away from the thermostat 

[Dr Bob]

2 hours ago, Tonka said:

 

Ok, thats the heatmiser which looks totally different to the google nest. The nest has a red +ve and brown -ve feed which I will take from the boat circuits then has a wire out that is the 'call for heat' wire to the webasto.

I cant see properly from the pic but there seems to be 3 wires from the square female connector - a red (so +12v and two others. I suspect one is black and goes to the A2 - so that is the 'call for heat' and the other one is brown and goes to the unmarked screw (or is it a -ve?)

 

On my webasto switching box, I have  a red, a brown and 2 blacks. Is it any of the two blacks I need to use?

 

 

Edit

Ah rather than just looking  at the picture, I have now read the words (I am a muppet.....whadyou expect). Now clear. I'll try and wire it up on the weekend. Many thanks.

Edited January 12, 2023 by Dr Bob

[GUMPY]

Are you sure its analogue and not W-BUS , if its W-BUS you will need some form of converter

 

[Dr Bob]

46 minutes ago, Loddon said:

Are you sure its analogue and not W-BUS , if its W-BUS you will need some form of converter

 

Not a clue. My bus pass has now expired.

 

The guy's next door system works fine - with the same webasto heater and a google nest. I just needed to know how to wire it and Tonka's picture shows that.

[ditchcrawler]

1 minute ago, Dr Bob said:

Not a clue. My bus pass has now expired.

 

The guy's next door system works fine - with the same webasto heater and a google nest. I just needed to know how to wire it and Tonka's picture shows that.

Sneak in and take it to bits when he is not looking

[Mike Todd]

18 hours ago, Dr Bob said:

Not a clue. My bus pass has now expired.

 

The guy's next door system works fine - with the same webasto heater and a google nest. I just needed to know how to wire it and Tonka's picture shows that.

Much the same with us. We very quickly tired of the inadequacy of the Webasto standard controller offers, which was what the boat builder installed. We convinced him that it was inadequate and also that the thermostat (part of the controller) was inside the cupboard with all the fuses and wiring, but especially the inverter. Hence it was not much cop as a guide to cabin temps. In fact he willingly swapped for a heat miser in the main cabin - at least he knew where the wires were buried!

[robtheplod]

Following on from this as I'm looking to control my Webasto via a relay i can remotely activate. Using the above equipment I'm assuming the device works by connecting A1 and A2 ... can anyone confirm?   (mine is analogue) - trying to get a clear idea of the wiring..

[Midnight]

On 12/01/2023 at 16:53, Dr Bob said:

I'm getting cheesed off with my Webasto control thingy giving me little control. Great, you can program it to come on 3 times a day but it never switches off.

 

I'm going to fit a google nest but what wire do I need to connect for the 'request for heating'?

Looking at the 4 wires going into the controller, there is one red, one brown and two black. I assume from looking at wiring diagrams the red is the +ve, the brown the -ve and the blacks then must be the request for heat wires.

I am guessing if I put 12v down the black wire from the google nest, the webasto will fire up.

The guy on the boat next to use wired his up that way but he's not around to work out which wire he used!

 

I have my Webasto switched on/off by a Propex timer & wall stat with a relay to stop it switching off during a timed cycle. If it's cold it runs a timed program. If it's not cold it doesn't run - simples.

[robtheplod]

2 hours ago, Midnight said:

 

I have my Webasto switched on/off by a Propex timer & wall stat with a relay to stop it switching off during a timed cycle. If it's cold it runs a timed program. If it's not cold it doesn't run - simples.

fab.. can you recall which wires the relay connects?

[Midnight]

1 hour ago, robtheplod said:

fab.. can you recall which wires the relay connects?

 

Here's the diagram. It's ages since I set this up for a Mikuni but I don't remember changing much when it was replaced by the Webasto. My mate wired in the Webasto but if you figure out which switch permanent live wire is required it should be straight forward. I think the live to the Propex timer just piggybacks to the permanent live from the Webasto control switch.

 

 

 

Edited July 11, 2023 by Midnight

[Dr Bob]

6 hours ago, robtheplod said:

Following on from this as I'm looking to control my Webasto via a relay i can remotely activate. Using the above equipment I'm assuming the device works by connecting A1 and A2 ... can anyone confirm?   (mine is analogue) - trying to get a clear idea of the wiring..

I sorted mine very easily. All you need to do is send 12v + down the black wires with the negative connected to the batttery ground to fire up the Webasto. My google nest is working perfectly and I can fire up the heating remotely if needed.

[robtheplod]

Just thought I'd give an update here. I wired up my Webasto to my Victron Cerbo GX (Relay 1 terminals) - just need to connect the black and red wires and bingo it works like a charm. Thanks for all the help. Now can get the boat warm in plenty of time for when we use it in the winter!

[bigcol]

On 12/01/2023 at 19:16, Dr Bob said:

 

Ok, thats the heatmiser which looks totally different to the google nest. The nest has a red +ve and brown -ve feed which I will take from the boat circuits then has a wire out that is the 'call for heat' wire to the webasto.

I cant see properly from the pic but there seems to be 3 wires from the square female connector - a red (so +12v and two others. I suspect one is black and goes to the A2 - so that is the 'call for heat' and the other one is brown and goes to the unmarked screw (or is it a -ve?)

 

On my webasto switching box, I have  a red, a brown and 2 blacks. Is it any of the two blacks I need to use?

 

 

Edit

Ah rather than just looking  at the picture, I have now read the words (I am a muppet.....whadyou expect). Now clear. I'll try and wire it up on the weekend. Many thanks.

 

Hi there

 

please help, all I want is to switch the heater on or off 

I have 2 reds that go to + and A1 these are linked

have a black going toA2

and a brown going to —

 

if I just wanted a on off switch what would I need to do?

what wire needs to be joined etc

[Tonka]

14 minutes ago, bigcol said:

 

Hi there

 

please help, all I want is to switch the heater on or off 

I have 2 reds that go to + and A1 these are linked

have a black going toA2

and a brown going to —

 

if I just wanted a on off switch what would I need to do?

what wire needs to be joined etc

Hi Colin, do you  have a wiring diagram for the Webasto. I shall have a look later for a softcopy and send it over

[Martin Nicholas]

The black to 12V switches a Thermo 90 on and off - from the Installation Instructions.

[Jen-in-Wellies]

23 minutes ago, Martin Nicholas said:

The black to 12V switches a Thermo 90 on and off - from the Installation Instructions.

Confirm that this works on Webasto models that don't use Wbus communications between accessories. Thermotop C are fine, but the Evo uses wbus.

[Tonka]

1 hour ago, bigcol said:

 

Hi there

 

please help, all I want is to switch the heater on or off 

I have 2 reds that go to + and A1 these are linked

have a black going toA2

and a brown going to —

 

if I just wanted a on off switch what would I need to do?

what wire needs to be joined etc

12 v goes into the Heatmiser switch on A1 and then the switch puts the 12v through to the A2 connection. 

Once the steam laptop powers up I will put the heatmiser manual up

[Tonka]

Here is the full Heatmiser manual

Heatmiser.pdf

[bigcol]

Thank you Tonka, your a star!!