Baxi CH Problems Can anyone help Pease

[ukspartan]

the system is a gravity fed Baxi back boiler that has begun to malfunction. Timer control unit looks ok, 3port valve is not switching over at all, I presume it's faulty or not receiving power because of either a thermostat or controller malfunction,will order motorised valve top box, have also ordered new thermostat

The only way to get the heating to work is to set motorised valve to locked off midway position opening all ports with both heating and water switched on at the timer, but as soon as the hot water fills cylinder and is shut off by the cylinder stat the heating side stops working also.

Have resorted to filling bath with hot water and then leaving bathroom sink hot tap running , this keep all rads hot enough to keep house reasonably warm during this cold snap.

I'm wondering if a frozen header tank has kicked all these problems off but there have been no unusual boiler noises, the system will be getting a good flush through now but when bleeding the rads water looks clean

What tests can I do to check if Timer , Valve , and Thermostat are all functioning ok pls? I do have a multimeter if required

Many thanks in advance

Peter

 

[Terry_the_piper]

Check cyl stat is sending satisfied signal back to junction box.

 

[tom609]

motorised valve is common fault and your symptons appear to have all the indications of a faulty actuator

 

[Leo21]

All the faults you've listed point faulty sycron motor, divertor head or room thermostat. When any of these fail the heating stops working when the hot water is satisfied. I'm not keen on advising you on testing voltages, not knowing your competence.

 

[plumber0808]

I realise you want to try and sort the problem yourself, but instead of ordering parts until you solve the problem I would recommend getting someone competent in to test and diagnose the faulty part/parts. I know everyone's trying to save money where they can, me included, but things can go **** up very quickly.

 

[jtsplumbing]

For what you will pay for just the power head for your valve, you will be better to replace the complete valve, dont bother with other items untill you have sorted diverter valve, this may solve all the problems ! was everthing OK untill the valve stoped working ?

 

[ukspartan]

Big Thanks to all that have replied !!

the problem is the 3 port motorised valve, With the actuator box removed there is very little movement in the key. and the motor is stuck and making a wirring clicking sound.

I'm having trouble finding a new valve. The one fitted is Honeywell F4 9845 .Can anyone tell me if Honeywell V4073A1039 is an equivilent ? It appears to have all the same functions, or is there any other better versons that would do the job?

 

[ukspartan]

motorised valve is common fault and your symptons appear to have all the indications of a faulty actuator

Yes you were right,it is the valve, now looking for Honeywell F4 9845 replacement which appears to have been discontinued , can you point me towards an updated version?

many thanks

 

[ukspartan]

For what you will pay for just the power head for your valve, you will be better to replace the complete valve, dont bother with other items untill you have sorted diverter valve, this may solve all the problems ! was everthing OK untill the valve stoped working ?

sound advice, ys diverter needs changing and original Honeywell F4 9845 discontinued, is there something in the V4 range to replace it ?
in answer to yr q ,System has always given very good service and was working perfectly until the cold weather started a week ago then developed a lot of pilot light probs and the valve prob , will have to check header tank isn't frozen does that happen a lot in yr experience? The thermostat was over 10 yrs old and needs swapping out , do you recommend a digital replacement and are they complicated to fit to this older system?

many thanks

 

[tom609]

call honeywell on monday they will point you inthe right direction

 

[ukspartan]

I replaced Honeywell with Tower VAL322MP mid-position valve , cost about half price with 3 yr gt , is doing the job perfectly well . Also replaced the thermostat which was 15 yrs old , system now running much better and heating feels much more balanced as the new stat is coming in and out when it's meant to

Thanks to all who replied !!
:yes: :44: :yes:

sound advice, ys diverter needs changing and original Honeywell F4 9845 discontinued, is there something in the V4 range to replace it ?
in answer to yr q ,System has always given very good service and was working perfectly until the cold weather started a week ago then developed a lot of pilot light probs and the valve prob , will have to check header tank isn't frozen does that happen a lot in yr experience? The thermostat was over 10 yrs old and needs swapping out , do you recommend a digital replacement and are they complicated to fit to this older system?

many thanks

 

[Leo21]

Those tower valves aren't great quality, in future I would recommend you use Honeywell. The tower might have a three year warranty, but you'll have to change it for free if it goes wrong.

 

[ukspartan]

You were right about Tower, after 1 week of operation the top box has became completely jammed up . They are sending a replacement but I will take your advice and swap this out for a Honeywell at the earliest opportunity.

Meanwhile the boiler is now tripping out after about 10 minutes of running ,the pilot , everything then needs re starting, it's enough to give us some warm radiators or a tank of hot-ish water. it's been a bit of a struggle during this cold weather as we have a young baby to look after. I am going to flush out the system today any advice on what chemical flush to use would be good.


Could the boiler tripping out be caused by an air lock ? Are there bleed valves for the boiler feed?


Thanks to everyone that has replied !! :smiley2:

Those tower valves aren't great quality, in future I would recommend you use Honeywell. The tower might have a three year warranty, but you'll have to change it for free if it goes wrong.

 

[tom609]

why dont you use the manual lever to lock it on for you heating that way you will get your heating on at least when the boiler fires up

 

[Leo21]

To be honest if you've got a boiler fault you'll need a gas safe engineer to attend the boiler.