Help required wiring my ASHP/UFH

[ProDave]

I presume MCBO you really mean RCBO

 

The one problem with them is when they trip, you don't know if it's tripped because of overload, or because of earth leakage.  Do you have any ordinary circuits you could temporarily try it on (or swap the rcbo for an mcb, just for a test)

[joe90]

7 minutes ago, ProDave said:

I presume MCBO you really mean RCBO

 

Brain freeze, yes Dave, RCBO. Weird because if I disconnect the switch wires (dry contact) on the room stat it does not happen, when the switch wires are connected a flash appears in the back of the stat and the RCBO trips when the stat calls for heat, the 3 amp fuse does not blow so I guess it’s an earth fault, but these low voltage wires are not connected to the mains. Tomorrow I will see if either the live or neutral going to the stat connects to the switch wires in the stat, which I think would be an internal fault in the stat.

[dpmiller]

^didn't you already test for that tho, as Dave recommended?

[ProDave]

An alternative simple test is a simple mechanical thermostat to start with.

[joe90]

Builders have turned up to erect the conservatory, when I have got them settled in ( making tea!) I will start by checking everything and run more tests.

 

watch this space.........

[Jeremy Harris]

I've managed to find some more info on the thermostat you have, and it seems there are three variants.  I've attached the pdf to this, but you may already have it.

 

The part numbers vary for each model:

 

E91.713 and E91.716 are mains output units (not isolated) with the first being the 3 A version and the second being the 16 A version.  They have markings that look identical to those on your unit.

 

E91.723 is the version with potential-free contacts on terminals 4 and 5, and looks different to the unit you have.

 

E9_manual.pdf

[joe90]

Jeremy, you are a star (again). I have the 713 and looking at the connection tabs on the photo below I was confused by the writing and rang Wunda tech services and they told me the manufacturer printed them wrong and it was an isolated switch contact. Just checked it and yes when the stat calls for heat it produces 240v across n1 - l1.

 

i suppose I will have to drive a relay with this to give me switch contacts to switch the ASHP call to heat? Luckily I have just bought two mains relays (one fir the MVHR using a humidistat). I just hope applying mains across the 12v supply in the ASHP has not done any damage.?

Edited October 3, 2018 by joe90

[Jeremy Harris]

I hope it's not done any damage, too.  With luck the 12 V connections in the ASHP have some form of protection. 

 

If there is damage, and as Wunda told you that the thermostat had dry contacts, I wonder if you could claim against them?

 

 

[ProDave]

Just link out the call for heat contact at the ASHP and power it up and see if it works.

[Jeremy Harris]

Both contacts need to be linked to get it to turn on and provide heat - link 0 V (terminal 3) to both terminals 6 and 7 and the ASHP should just turn on and run.

[joe90]

Bollocks, no joy, the GMC board has an led and this was flashing at 1/2 hz yesterday, nothing now. Checked mains going in and 5 amp fuse on the board is ok. 

 

“There is a LED on the GMC board that displays any board errors. The error code can be identified from the flashing LED using the following
table. In the case of more than one error, the error with the highest priority will be displayed until it is resolved.
In the case of normal operation, the LED flashes at a frequency of 1⁄2 Hz.

frequency of 1Hz, it flashes a number of times equal to the error code
Diagnostic 6

the flashing is interrupted for 2 seconds between the first and second digits.”

 

I really dont don’t know where I go from here.

[Triassic]

You’ve got to wonder if the mains voltage hitting the board has killed it !? Sorry......

[joe90]

Just now, Triassic said:

You’ve got to wonder if the mains voltage hitting the board has killed it !? Sorry......

Yup, that’s my worry. The command unit still appears to be working, displays everything except outdoor air temp! .

[ProDave]

Wasn't there another thread a few days ago about someone killing the same board by shorting out the 12V?

 

First think is check id the 12V DC supply on the board is working.

[Jeremy Harris]

12 minutes ago, joe90 said:

Yup, that’s my worry. The command unit still appears to be working, displays everything except outdoor air temp! .

 

 

The command unit is powered from the low voltage supply on the ASHP main board, so it looks like the power is there.  The outdoor temperature and humidity data is processed by the main board in the ASHP and transmitted via a serial data link to the command unit, so it looks very much as if the data handling and control side of the main board has failed, rather than the power supply. 

 

I suspect a new main board will be needed, but at least you have the command unit, so can programme it with the settings you need, even if it's just to download all the default settings into non-volatile memory on a new board.  It may be that a new main board comes with all the defaults programmed, but it's possible that, like a boiler main board, it doesn't, and needs to be initially programmed by connecting the command unit.

 

A new main board seems to be around £100, from that other post; maybe you should try and get Wunda to stump up for it, as they told you that the thermostat had dry contacts when it didn't.

[Triassic]

15 minutes ago, ProDave said:

Wasn't there another thread a few days ago about someone killing the same board by shorting out the 12V?

 

First think is check id the 12V DC supply on the board is working.

 

[joe90]

I think I am going back to bed!!!!. Just sent Carrier a message explaing the problem and asking what to check if anything and what price a New board if required. I am definitely sticking to woodwork in the future?.

[PeterW]

I’d be telling Wunda to pay up as they have clearly misled you and caused damage. 

 

@Hecateh are these the stats that Wunda have sent you too..?? 

[Jeremy Harris]

18 minutes ago, PeterW said:

I’d be telling Wunda to pay up as they have clearly misled you and caused damage. 

 

 

I'd be telling Wunda to pay up too!

 

I can only find one supplier listing that board, no price and they are in the Netherlands: https://www.smith-europe.eu/en/sales/marine-refrigeration-parts-list/carrier-marine-parts-14/

 

There's a long list on that page, but the board part number is listed a long way down; search the page for B036601H03

[Ed Davies]

10 minutes ago, PeterW said:

I’d be telling Wunda to pay up as they have clearly misled you and caused damage. 

 

I'd imagine this is the sort of consequential loss that terms and conditions exclude so legally they're probably in the clear. But morally, especially as @joe90 specifically checked with them, they'd be asking for a bad reputation if they don't at least contribute substantially to the replacement.

[joe90]

Thanks Jeremy, I have messaged these people in France to see what price, availability, and postage . Also waiting to hear back from Carrier. 

 

Thanks guys, will post replies.

[Jeremy Harris]

Just realised they are in the Netherlands, rather than France, even though they give a contact in France it's a Netherlands country code on the number.

[joe90]

1 minute ago, Ed Davies said:

 

I'd imagine this is the sort of consequential loss that terms and conditions exclude so legally they're probably in the clear. But morally, especially as @joe90 specifically checked with them, they'd be asking for a bad reputation if they don't at least contribute substantially to the replacement.

 

I will be ringing them, I spoke to Chris so know who I dealt with. May also follow it up with an Email. If nothing else perhaps it will stop it cocking up someone else’s ASHP.

 

Although this is annoying if it does cost me £100 it’s still a cheap deal as I bought the ASHP for £850 delivered. I was just dreading having the same problem as @ProDave and I bought mine from a person privately not a company.

[Ed Davies]

1 hour ago, joe90 said:

Bollocks, no joy, the GMC board has an led and this was flashing at 1/2 hz yesterday, nothing now.

 

Just to be clear, what does “nothing now” mean? LED off all the time? LED on all the time? LED still going at 1/2 Hz? I'd assume the first but as well to be sure.

[Jeremy Harris]

From the lack of external data being displayed on the command unit, and the fact that the command unit is still working, we can deduce that the 12 V supply is OK, as it runs the command unit (there's a 4 wire power and data cable between the command unit and the ASHP main board) and that data is not being transmitted by the ASHP to the command unit, as the external temperature and humidity isn't being displayed.

 

The serial data link is RS485-like, although it seems to use a proprietary data format.  I did have a go at sniffing the data to try and see if there was a way to programme the ASHP non-volatile memory without using a command unit, as one or two here have bought units where the command unit wasn't supplied (including @joe90, I believe).  Kingspan seemed to sell these units without the command unit, whereas Glowworm sold them with.  Not sure about the other badged versions of the same unit. 

 

Once programmed, the ASHP does run perfectly well without the command unit, but there's then no way to change things like the weather compensation curve or any other temperature set points.  The command unit can be used as a programmable thermostat, as well as just a programming interface, so can replace the default dry contact switching system these ASHPs use.  The only downside of that it that the command unit human interface is a bit clunky, IMO, and not at all intuitive to use as a programmable thermostat.