Microgenius 23 MFFI Fault

[TerryWaite]

I have a customer with a complaint on a microgenius 23MFFI, the hot water takes ages to come through, and when the hot water is on, the radiators heat up. Is it the diverter valve?

And if so is it a new diaphragm or a complete unit? And how difficult is it? Done a few breakdowns but done done a diverter valve yet

Many thanks in advance

 

[diamondgas]

Hi TerryWaite

Could be a cupl of issues to be honest. Changing the diverter may not help though! Do you know anyone with a bit more experience who can hands on help you out? Why not ask them? That way you learn IMHO!

You're looking at heat transfer issues and the water diverting where you wouldn't expect it to! That initially indicated diverter or phex! imo Got to check a few things along the way though

 

[Puddle]

As you say probably diverter valve,these have the black head motor unit on top,to push diverter up and down,you can get a full service kit for diverter valve,check motor ok and flow switch not sticking,would replace top section of diverter valve as due to age will start leaking through seal if not already

imho

 

[ambrosia]

Could be a cupl of issues to be honest. Changing the diverter may not help

okay now you got me worried, had the same issue with a vaillant 242, i assumed it was a diverter valve and confidently told the owner so. I'm going back to fit it monday, if its not the diverter valve theyre gonna realise the inexperienced idiot i really am.
I dont think its the micro switch as i took it off and seems to be working, I also dont think its the PCB as the microswitch was working.
what were the other issues it could be so i dont look like a complete fool

 

[Millsy 82]

okay now you got me worried, had the same issue with a vaillant 242, i assumed it was a diverter valve and confidently told the owner so. I'm going back to fit it monday, if its not the diverter valve theyre gonna realise the inexperienced idiot i really am.
I dont think its the micro switch as i took it off and seems to be working, I also dont think its the PCB as the microswitch was working.
what were the other issues it could be so i dont look like a complete fool

On yours have a look at the white lever on the right hand side which pushes down the micro switch if that is not moving or hardly moving it is the diverter valve if it is pushing down the micro switch fully then you will be looking at a plate

 

[Millsy 82]

To the OP

Chances are is that it is the diverter remove it and have a look at it if it is covered in black gunk look at the plate and see if thats full of gunk.

 

[TerryWaite]

Thanks for the replies.

I went round today and had a little look. The hot water flow sensor seems fine, the led on the top lights up when the hot tap is turned on, I did notice that when ch mode was selected it sounded like the motor was really struggling, think the motor has given up the ghost.

Also, as puddle says, the top of the diverter valve is leaking I seen the calcified residues all over it. Does this mean I will need a new complete valve and motor? What are the service kits, what bits do you get and are they any good?

 

[TerryWaite]

To the OP

Chances are is that it is the diverter remove it and have a look at it if it is covered in black gunk look at the plate and see if thats full of gunk.

Thanks very much. What do you mean by the plate?

 

[Millsy 82]

Plate to plate heat exchanger

 

[TerryWaite]

how would you test if the motor was knackered? resistance test the pins?