Sorry forgot to mention i changed the diaphragm inside the water section.
Vaillant VCW 221H hot water and now heating problem.
- Thread starter archyM
- Start date
I will repeat as you have not apparently fully understood what you have been told.
These are a very complicated design and its beyond probably 98% of practising boiler engineers.
In reality the boiler is very reliable and the faults usually simple to identify and fix when in front of the boiler.
I am happy to go to repair them but I have only ever met one person who seems totally comfortable with them.
I will say that you are doing quite well for a DIYer but then you have the time and inclination. The Vaillant manuals are generally pretty unhelpful as they dont explain how each opart works.
This is one situation when I would not even advise you to "get someone in" unless it was one of the fixed price repairs by BG as whoever it is will be likely to struggle!
Tony
These are a very complicated design and its beyond probably 98% of practising boiler engineers.
In reality the boiler is very reliable and the faults usually simple to identify and fix when in front of the boiler.
I am happy to go to repair them but I have only ever met one person who seems totally comfortable with them.
I will say that you are doing quite well for a DIYer but then you have the time and inclination. The Vaillant manuals are generally pretty unhelpful as they dont explain how each opart works.
This is one situation when I would not even advise you to "get someone in" unless it was one of the fixed price repairs by BG as whoever it is will be likely to struggle!
Tony
N
namsag
Did you drain it down to change bits or just turn water off and open tap. If you have drained it getting air out of little tiny tubes so it works again can be a pain . As said before prob is probably the servo valve but it is far better to be in front of it and see exactly what is happening an what noises it` making.
Most engineers who can follow straight forward hydraulics will find this boiler easy
Ignore Agile he is one of those 98 percent of people he claims who doesn`t understand how this boiler works and is just hi jacking yet another topic to try and look clever by insulting a diy poster.
Why not suggest something Agile instead of trying to look clever on other peoples backs
Most engineers who can follow straight forward hydraulics will find this boiler easy
Ignore Agile he is one of those 98 percent of people he claims who doesn`t understand how this boiler works and is just hi jacking yet another topic to try and look clever by insulting a diy poster.
Why not suggest something Agile instead of trying to look clever on other peoples backs
I think that I was being realistic about this model.
At least I dont abuse anyone like many ex-British Gas seem to !
In fact rather than insulting the OP as you claim, I was being complimentary saying "I will say that you are doing quite well for a DIYer".
I also post under my own name rather than an anonymous forum name.
Tony
At least I dont abuse anyone like many ex-British Gas seem to !
In fact rather than insulting the OP as you claim, I was being complimentary saying "I will say that you are doing quite well for a DIYer".
I also post under my own name rather than an anonymous forum name.
Tony
N
namsag
How do you know he HAS NOT FULLY UNDERSTOOD WHAT HE HAS BEEN TOLD.
I would imagine for most engineers this is a relatively simple boiler. Only those wanting to pretend to customers or cannot understand basic hydraulics would struggle
Who is British Gas then explain to me who this company is then seeing as you always mention them
And you still have not suggested snything to sort problem with boiler
And would that company name you post under be Agile sevices ltd of evelyn ave coventry
I would imagine for most engineers this is a relatively simple boiler. Only those wanting to pretend to customers or cannot understand basic hydraulics would struggle
Who is British Gas then explain to me who this company is then seeing as you always mention them
And you still have not suggested snything to sort problem with boiler
And would that company name you post under be Agile sevices ltd of evelyn ave coventry
If you have drained the c/h side of the boiler then you most prob have air trapped . The auto air vents can sometimes get blocked and so air doesn`t escape. may need cleaning/replacing.
Sometimes turning the boiler on and off stops /starts pump and helps push the air into the c/h system
Q When you turn on the hot tap does the arm on the right hand side of the diverter( where 2 m/switches are)? They should.
Q When you turn c/h on is it pulled inwards closing the contacts on the microswitch.If only slightly out the arm can be adjusted by slackening off the nut and moving arm inwards slightly.
Sounds to me you have air in boiler though.
These boilers are not too complicated just engineers are generally scared to work on them.
Sometimes turning the boiler on and off stops /starts pump and helps push the air into the c/h system
Q When you turn on the hot tap does the arm on the right hand side of the diverter( where 2 m/switches are)? They should.
Q When you turn c/h on is it pulled inwards closing the contacts on the microswitch.If only slightly out the arm can be adjusted by slackening off the nut and moving arm inwards slightly.
Sounds to me you have air in boiler though.
These boilers are not too complicated just engineers are generally scared to work on them.
Hello,
I did not quite get the question posted by Werewolf regarding 2M switches is there a part missing?
Can i release air out of the system through the pump if that is running and heating is not working. But then again the jets are not firing up for either hot water nor heating so one would need for those to be working first in order to say pump has air and therefor is not circulating well enough if at all. Do correct me if i am wrong.
I shall have another look at the boiler this weekend and hopefully all is fine.
Finally any remarks made regarding not understanding, i take with a pinch of salt, then again i did receive pat on the back as i am now a good DIYer, this is also fine.
No seriously all i am doing is trying to understand how to repair any fault if it is repairable. Just because the boiler is 13 years old and some people do not wish to tackle the problem and would rather install a new boiler.
Personally if this all goes well and i do not have to do anything else as in the terms of buying more parts etc. then i have done a job costing me £3.35 for diaphragm and £2.85 for 4 water section pins( aren't they a bit expensive?) and my time effort.
Along with all this i shall have a much better understanding of heating systems and boilers in the future and this is mainly thanks to people on this site especially the ones who have posted.
Again all responses much appreciated.
I did not quite get the question posted by Werewolf regarding 2M switches is there a part missing?
Can i release air out of the system through the pump if that is running and heating is not working. But then again the jets are not firing up for either hot water nor heating so one would need for those to be working first in order to say pump has air and therefor is not circulating well enough if at all. Do correct me if i am wrong.
I shall have another look at the boiler this weekend and hopefully all is fine.
Finally any remarks made regarding not understanding, i take with a pinch of salt, then again i did receive pat on the back as i am now a good DIYer, this is also fine.
No seriously all i am doing is trying to understand how to repair any fault if it is repairable. Just because the boiler is 13 years old and some people do not wish to tackle the problem and would rather install a new boiler.
Personally if this all goes well and i do not have to do anything else as in the terms of buying more parts etc. then i have done a job costing me £3.35 for diaphragm and £2.85 for 4 water section pins( aren't they a bit expensive?) and my time effort.
Along with all this i shall have a much better understanding of heating systems and boilers in the future and this is mainly thanks to people on this site especially the ones who have posted.
Again all responses much appreciated.
"""But then again the jets are not firing up for either hot water nor heating so one would need for those to be working first in order to say pump has air and therefor is not circulating well enough if at all. Do correct me if i am wrong."""
You are making your own assumptions again here.
Think about it, the air can be bled from the pump regardless of the gas being burning or not.
Bleed the pump with it off and then on and then again with it off.
If the water is not circulating properly then the boiler will not fire up !!! Bleed air out first and then the gas can fire ( if there is no other problem! )
Tony
You are making your own assumptions again here.
Think about it, the air can be bled from the pump regardless of the gas being burning or not.
Bleed the pump with it off and then on and then again with it off.
If the water is not circulating properly then the boiler will not fire up !!! Bleed air out first and then the gas can fire ( if there is no other problem! )
Tony
Hello again,
I have come to battle it out again with this boiler. The heating has been fine when switching over to central heating. The problem remains still with the hot water. Most times it will not work when hot water tap is turned on. Werewolf i have observed overtime and the arm on side of diverter does not move out to the right, when there is no hot water.
It has been a fair time since i have contacted you guys, truth be known i gave up on it and thought as the boiler is quite old it may be wise to let it run it's course. Therefore whenever there was no hot water i had been turning on the CH for about 5 to 10 minutes after which would open any HW tap and would have hot water.
Water pin is rising, switch is being made pump is running etc. As you hopefully are aware diaphragm was replaced in water section. I am thinking it must be something over the divertor valve side, especially as the arm does not move out to the right.
I must try all avenues before completely giving up. I appreciate all responses.
I have come to battle it out again with this boiler. The heating has been fine when switching over to central heating. The problem remains still with the hot water. Most times it will not work when hot water tap is turned on. Werewolf i have observed overtime and the arm on side of diverter does not move out to the right, when there is no hot water.
It has been a fair time since i have contacted you guys, truth be known i gave up on it and thought as the boiler is quite old it may be wise to let it run it's course. Therefore whenever there was no hot water i had been turning on the CH for about 5 to 10 minutes after which would open any HW tap and would have hot water.
Water pin is rising, switch is being made pump is running etc. As you hopefully are aware diaphragm was replaced in water section. I am thinking it must be something over the divertor valve side, especially as the arm does not move out to the right.
I must try all avenues before completely giving up. I appreciate all responses.
Replace the auto air vent - with any trapped air and an old blocked aav your going nowhere.
Is the pin between the water section and the cam adjusted correctly? If not the cam will not rotate sufficient to reverse the diff. pressure on the diverter.
Is the DHW microswitch adjusted correctly? - again it has to be set correctly.
Does the diverter valve operate and move sufficient to operate the 2 microswitches?
Are the microswitches correctly adjusted?
If so perhaps the problem lies in the hydraulic gas valve operator - maybe there is insufficient diff. prerssure in DHW mode to move the pin.
Within the servo valve above the water section is an arrangement of ceramic discs (similar to quarter turn taps). Sometimes due to scale/debris these discs do not allow the full differential pressure across the diverter - in effect the discs let by since they are no longer in close proximity. Either carefully strip down and clean or replace.
Next check the control tubes are clear and the restriction in the banjo connection.
Next strip down the diverter and check/refurb
Unfortunately manuals are not particularly helpful. A Haynes manual will show you how to strip down and rebuild a car gearbox but it won't tell you how to check for wear on the baulk rings and cones on the synchro hubs. Boiler manuals are no different - its all down to experience.
Is the pin between the water section and the cam adjusted correctly? If not the cam will not rotate sufficient to reverse the diff. pressure on the diverter.
Is the DHW microswitch adjusted correctly? - again it has to be set correctly.
Does the diverter valve operate and move sufficient to operate the 2 microswitches?
Are the microswitches correctly adjusted?
If so perhaps the problem lies in the hydraulic gas valve operator - maybe there is insufficient diff. prerssure in DHW mode to move the pin.
Within the servo valve above the water section is an arrangement of ceramic discs (similar to quarter turn taps). Sometimes due to scale/debris these discs do not allow the full differential pressure across the diverter - in effect the discs let by since they are no longer in close proximity. Either carefully strip down and clean or replace.
Next check the control tubes are clear and the restriction in the banjo connection.
Next strip down the diverter and check/refurb
Unfortunately manuals are not particularly helpful. A Haynes manual will show you how to strip down and rebuild a car gearbox but it won't tell you how to check for wear on the baulk rings and cones on the synchro hubs. Boiler manuals are no different - its all down to experience.
archyM, if you have not worked on this boiler before (looks like it as your questions suggest you do not know how the boiler works- you are guessing what might be wrong), I would strognly suggest you look out for someone who understands this boiler operate sequence (gasguru has prpared the path for you), so should be able to fix it instead of selling you a replacement.
Great boiler, but a bad boiler for the partchangers.
Great boiler, but a bad boiler for the partchangers.
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