Baxi Duo-Tec divertor motor

[m4rky]

And did you check if the valve has a bypass pipe at the back (i think the 40 does). Check with the power off.

I haven't checked yet. I did read somewhere when looking for cartridge prices that the Duo-tec HE "A" models don't have a bypass. Mine is the "A" model and I can't see one on the diagrams in the instruction manual.

But will check tomorrow.

 

[m4rky]

Turn power off, take head off, turn upside down and get someone to turn tap on and off, you should see the centre pin going in and out. Did you feel the flow pipe when the tap is running ? I know you say HW is ok but this is a quick check to see if diverters passing. And did you check if the valve has a bypass pipe at the back (i think the 40 does). Check with the power off.

OK I took the motor off the valve and turned the hot water tap on.
Nothing moved on the motor as the power was off.
But I felt nothing move inside the top of the valve.
Hot water came out of the tap.
The hot water out pipe was hot, but it was beforehand.
I could only see two pipes coming into the valve at the bottom labelled Heating Flow and Domestic Hot water Outlet. There is a third pipe on the left labelled flow pipe and it is also attached to the heat exchanger.

 

[m4rky]

Can someone explain how the diverter valve motor work on the Duo-tec?

Does the motor push the pin down in the diverter valve cartridge?

Or does the pin in the diverter valve push up into the motor and this starts the boiler?

Thanks

 

[Gasguru]

The actuator pushes down on the pin in the diverter.

The actuator head moves a pin up and down but since there's an O ring seal, the pin (if in the fully out position) may stay in that position despite the motor rotating the cam inside to the fully in position.

So to test it you need to hold the motor with the pin facing up. Insert a small pin or screwdriver to ensure the pins pushed down. Then check the pin rises when the motor operates for DHW or HTG.

 

[DP]

Will repeat what gigs asked
'What cost you £400 m4rky?

Clearly you have no idea what is involved or why you have a malfunction. Good luck

 

[St0rmer66]

I have the same boiler and had to remove the cartridge to replace the leaking gland seal just last week. If it's the "A" model it doesn't have a bypass.

Have you considered a fixed price repair from either Baxi (HeatTeam) or British Gas etc? Will include parts & labour and you know you'll get a result.

It does just sound like a sticking diverter cartridge to me though. Motor can get worn out by trying too hard to move a stiff spindle but if you catch it early enough can often be saved.

 

[m4rky]

Will repeat what gigs asked
'What cost you £400 m4rky?

Clearly you have no idea what is involved or why you have a malfunction. Good luck

Originally we had a leak from the diverter valve area. A part was replaced and it still leaked but not as bad as before. The system was then chemically cleaned and now the central heating only works a little bit. So I feel like I have forked out a lot of money to be in a worse state.

You are correct I don't know what is involved or why my heating is not working. I have lost trust with my plumber as he doesn't seem to be explaining well what it is I am paying for.
So I am trying to find out if what he saying about the boiler is possible/correct. I thought he had already replaced the diverter valve cartridge four weeks ago and now he is saying it needs replacing again but also needs a motor.
I don't see why I should pay again to replace a part that is four weeks old.
Also when he replaced the valve cartridge he said that he could not guarantee the fix unless the system had a chemical flush. So we had this done.

I have spoken again with the plumber and he is now saying that he did not replace the valve cartridge he just repaired it.
Also that it needs a new diverter valve (not just a cartridge) and motor (at a further cost of £230), therefore it is a different fault so not covered by the original fix.
He says you cannot replace just the cartridge on my boiler, it needs a whole new diverter valve.

Now from help on this forum I now what he means about not being able to replace the cartridge on a diverter valve with a bypass.
However, I do not believe my diverter valve is one with a bypass.
It doesn't seem to have the bypass pipe around the back of the valve.

So back to my original problem.

 

[m4rky]

The actuator pushes down on the pin in the diverter.

The actuator head moves a pin up and down but since there's an O ring seal, the pin (if in the fully out position) may stay in that position despite the motor rotating the cam inside to the fully in position.

So to test it you need to hold the motor with the pin facing up. Insert a small pin or screwdriver to ensure the pins pushed down. Then check the pin rises when the motor operates for DHW or HTG.

Thanks for the help. I didn't hold the motor upside down so will need to try this again. But surely the boiler will need to be on otherwise how can I check the pin moving when the Hot water is turned on? Then motor is electric?

 

[m4rky]

I have the same boiler and had to remove the cartridge to replace the leaking gland seal just last week. If it's the "A" model it doesn't have a bypass.

Have you considered a fixed price repair from either Baxi (HeatTeam) or British Gas etc? Will include parts & labour and you know you'll get a result.

It does just sound like a sticking diverter cartridge to me though. Motor can get worn out by trying too hard to move a stiff spindle but if you catch it early enough can often be saved.

Thanks for the advice. I might give Baxi a ring.

Yes it is the "A" model. Does the cartridge just lift out or is there a special tool/knack to doing it?