Mitsubishi Ecodan fault code

[Rockingit]

Have a M-Ecodan ASHP system installed by a firm that's now parted company from the builders, so no warranty backup, and the ball's landed in my court to pick up the mess (six installs, btw).

I've just done a callout to a non-working system which is flashing up an E9 code both at the tank end and compressor, and having found the service manual online it reads to me like either a loose connection or a faulty PCB.

Can anyone give me any immediate pointers for the morning?

It's an Ecodan PUHZ-W50VHA system.

 

[Marvo]

Here's a service manual for a start. I'll have a look later and see if I can decypher the fault codes into laymens terms for you. Ecodan PUHZ-W50VHA-BS Service Manual - Mitsubishi Electric

 

[Rockingit]

Cheers, appreciated. I found the manual and the code earlier, it's just knowing what to do with it!!

 

[Marvo]

Okay, the error 9 indicates a comms error between the outdoor unit and the indoor unit.

One of the primary suspects would be wiring fault or noise. I'd suggest the first place to start would be to prove the wiring between the outdoor and indoor, check continuity and IR between the wires themselves and earth with it disconnected. Also check your neutral connection on the power side, make sure it's not at a high voltage wrt earth. Also check the earth is good to both indoor and outdoor units.

If all else fails after checking for the obvious wiring and supply problems you'll probably need to try a new flow temp controller in the outdoor unit, maybe the main agent can test the existing control board if you take it to them or it would be handy if the customer had more than one of these units so you could swap parts between them.

The system you're working on has one of the newer generation HFC gasses in it and runs under very high pressures. If you're not FGas certified I'd suggest a risk assessment before undertaking any work on these units.

 

[Leesparkykent]

What FTC has been installed?

 

[Leesparkykent]

The connections between the FTC and the outdoor unit s2 and s3 are just a signal if I remember right, check these connection and prove continuity. Also check the dips witch in the unit sw8-3 is on.

 

[Rockingit]

Brilliant, thanks chaps. I'll check all the cabling through, my only thoughts are that its been up and running for about six months already (commissioned about 18 months ago) working perfectly except for a failed UFH stat which I know is unrelated to this.

 

[Rockingit]

I rang up Mitsubishi technical this morning and they explained its often just the system needs a reboot, in the right order. So I went to site and did just that and hey presto it sprang to life. Now investigating official Ecodan support/maintenance training options!!

 

[Marvo]

Glad it turned out to be that simple. Do you do a lot of HVACR work?

 

[Rockingit]

Glad it turned out to be that simple. Do you do a lot of HVACR work?

Well, not really per se, but I'm finding more and more A/G SHP's being installed and its always the same old story - a wet head playing in the high tech market and its 1/2 a day into the job before you get to hear "Sparks, what do you think this means?" which is then normally followed by "Can you do that for me?" when they see the wiring schematic!! So, I think its a sensible way forward to get trained up properly, especially as I think I could easily integrate it into my push for 'smarter homes/smarter living' philosophy.

 

[Marvo]

Are you allowed to work on controls for these types of units without an FGas qual in the UK? It's something of a gray area where I am as to where the legal line is that you can go to without FGas certification.

 

[Rockingit]

I think it's a grey area here, too. The installers manuals just ask you to join the dots, and for the electrical side of that you don't get anywhere near the actual compressor components its just supply, comms and then additional heat sources back at the tank. I don't know what's involved in getting FGas, guess that might be my next research!

 

[davesparks]

As far as I know Fgas is not too difficult to get.
Braize the pipes, operate the vacuum pump correctly and don't let the gas escape.

If a plumber can do it I'm sure we can!

 

[Leesparkykent]

One of my mates got put on the Mitsubishi ashp training day by his firm, he told me he was the only sparks in the room and said it was mainly about the plumbing side and only briefly brushed over the sparky side of things.

 

[Rockingit]

I'm actually contemplating doing the whole installers / sales / Partners scheme. The only downside is that I'll need to take a plumbing C&G!!