Vokera Linea 24 Hot water problems.

[emailpatch]

No Tony, definitely pushes in to engage the HW, when the motor is removed it allows the mechanical valve pin to come out and disconnect supply to the secondary HE. If the valve pin is then pushed in manually with a screwdriver ect you can hear the water flow around the HE and start to get hot. You were right in the sense that the normal position for the motorised valve is pushing out therefore boiler with the motor fitted does remain in HW mode normally but once removed it definitely goes into CH only.

 

[emailpatch]

Anyway the problem is that on occasions the motor is switching between HW and CH when I've checked the connection with the multimeter its switching after the two pins either side of the neutral get fed on and off for no apparent reason, in short, the motors working in and out because the feeds are telling it to go in and out. Is this a faulty PCB?
Steve.

 

[Agile]

What you have stated is not totally logical but that may be because you have not clarified if you mean the motor pin or the diverter pin.

My posting was in respect of all other boiler models!

Assuming you are correct and the Linea operates with diverter pin IN for DHW then thats obviously what the motor has to achieve.

Merely measuring the voltage as you have done will confuse you because a faulty motor can put the voltage onto the other supply pin.

To check the motor put mains on each outer pin in turn and see if it reliably goes to the appropriate position and stays there ! Its more likely to be a faulty motor than PCB !

Its unlikely to be the PCB because the relay powers either tag according to if its energised or not. To check it measure the voltage applied to the motor during DHW and then CH and see that its appropriately powered as expected.

Tony

 

[emailpatch]

Just to clarify, Motor diverter pin needs to be fully extended (out) to push onto the mechanical pin to divert the water past the secondary HE to give HW. Therefore when the motor is removed the mechanical pin (not motor) is allowed to relax back out and not divert water past HE, yes?
Would you try the motor first then, its just got chance of a Linea 24/28 pcb for £20 tonight.
Steve.

 

[emailpatch]

Already checked motor like you suggested confirmed in earlier post, motor extends and retracts reliably depending on the left and right feed. Also checked plug feeds and both show same voltage 233 ish.

 

[Agile]

A new PCB for £20 would be a bargain!

A s/h PCB for £20 a risk!

You might be able to apply logic to determine if the PCB is at fault. The relay will be de-energised in DHW and energised for CH.

Failure to energise will result in no CH when demanded but DHW all the time.

I am guessing how its been designed but thats what I would expect.

The motor is the cheaper part and the least reliable so its the first part to try if you are not sure. But if you have a cheap PCB......

Tony

 

[emailpatch]

It is a new PCB, the CH water never seems to fail so I follow your logic for the motor but I am right in thinking you would notice a intermittent fault on the CH side less because even if it was switching on and off on that side the rads would still get hot just take a little longer, yes?

Steve.

 

[emailpatch]

Sorry! CH never seems to fail sorry gettin late.

 

[emailpatch]

Checked the PCB feed and relay and the pcb feed swtiches from black to brown (motor in and out) starting to think it has got to be the PCB, water flow switch always ignites the burners what else could it be?

Steve.

 

[Agile]

I am not convinced that your problem necessarily lies with the diverter valve. If that were at fault then the boiler would always fire up but the water might go to the wrong place.

There is usually a system flow proving switch which has to be operated whatever the mode. I understand this is not always fitted to every Linea.

If yours has one then are you sure its always responding reliably?

Perhaps a repeat of the fault symptoms might be beneficial?

Tony

 

[emailpatch]

DHW sometimes runs cold then hot or just stays cold, Burners always ignite when hot tap is run, when the water turns cold the heat is transfered to the rads even when CH not turned on or even selected on the front panel, diverter valve pin goes in and out transfering the water from the secondary HE to the rads, checked the PCB and the feed for the diverter valve switches from black to brown (pin in pin out on the motor valve) the relay clicks repeatedly.

In a nutshell.

Steve.

 

[Agile]

If the 230v switches from black to brown with the motor disconnected then thats definately a PCB problem unless there is an external influence at fault.

Are you sure the supply is switched to the other wire and not to both together? If both are powered then it will rotate and cycle the pin every 4 secs. That could be a fault on the relay not spacing the NC/NO contacts.

Have you monitored the DHW flow swith to ensure it remains electrically activated during the fault condition?

Hopefully if you disconnect the plug from the motor during DHW delivery then it will run DHW all day?

Tony

 

[emailpatch]

If the 230v switches from black to brown with the motor disconnected then thats definately a PCB problem unless there is an external influence at fault.

Are you sure the supply is switched to the other wire and not to both together? If both are powered then it will rotate and cycle the pin every 4 secs. That could be a fault on the relay not spacing the NC/NO contacts.

Have you monitored the DHW flow swith to ensure it remains electrically activated during the fault condition?

Hopefully if you disconnect the plug from the motor during DHW delivery then it will run DHW all day?

Tony

Yes, to all really, definately switching feeds at the PCB end causing the motor to cycle in and out, open up the motor and contacts and gearing fine in there, the boiler defaults mode on the DHW so when the motor or the wiring is disconnected to it it works fine on HW. Had the main pcb out yesterday and checked for dry joints, none found but alot of IC's tranformer, relays could be anything.

 

[emailpatch]

Here again, I've now changed both the motor actuator and the Pcb, and I'm still getting hot then cold water when the tap is turned on, the burners stay lit, but I've now noticed that the screw tap on the hot water outlet on the bottom of the boiler make a screaming noise when opened, I know Im clutching at straws anyone any more idea's?
Steve.

 

[scatmanjohn]

Is the new motor still going in and out during a demand?