Boiler servicing - flue test nozzles not easily accessible

[SydDenham]

I have a Vokera Compact A combi boiler. All the clearance distances around it required by the manufacturer for servicing are good. However there is not very much space in front of the access caps/nozzles at the bottom of the flue. I understand that these caps are used when the boiler is serviced to check on the gas composition inside the flue.

I have been told that a standard gas testing flue kit has a straight unflexible copper tube that goes into the flue for testing. The issue is that because there is not a large clear distance in front of the caps, an unflexible tube would not fit in.

I am told that some engineer's use a flexible pipe to go inside the flue through the screw caps. Is that the case and can I expect all servicing engineers to have a kit that has the required flexible pipe?

Thanks

 

[Stigster]

There is a good chance that an engineer will not be able to service the boiler if he can't get a flue gas analysis. They will write that down as a fault on the service paperwork and may not even service any of it until that is accessible. Depending upon the flue terminal location they may however be able to get a reading there instead which may be acceptable. I only ever worked on oil though so gas boilers may be different in that regard.

 

[ShaunCorbs]

Any chance of a pic of your install ? Eg the flue

 

[SydDenham]

Thanks for your comments - here's some photos.

 

[ShaunCorbs]

That's not good where does that boxing go ?

 

[SydDenham]

That's not good where does that boxing go ?

It goes straight through the pitched roof into the vertical flue terminal.

The vertical flue terminal is accessible from an adjoining roof window but of course it's one of the new black plastic ones that look very watertight - and hence probably are also maybe "gas flue testing tight"....

 

[ShaunCorbs]

Any chance of a few more pics of the boxing and flue near the window ?

 

[Riley]

Another kitchen fitter master stroke

 

[SydDenham]

Any chance of a few more pics of the boxing and flue near the window ?

There you go:

 

[SydDenham]

Another kitchen fitter master stroke

Indeed! Although to be fair, the manufacturer's instructions don't refer to a space required in front of part of the flue.

 

[Riley]

Also you say you have a vokera yet the flue is clamped with a Vaillant clamp??? And the test points are common sense really

 

[SydDenham]

Also you say you have a vokera yet the flue is clamped with a Vaillant clamp??? And the test points are common sense really

Apologies - well spotted. It is indeed a Vaillant Combi not a Vokera.

 

[SydDenham]

Excuse my ignorance but is the following piece of kit the type of thing that the boiler engineer would need?

Because it's flexible, it would fit I believe.

Kane KMCP35 Combustion Probe for 250, 425, 450, 455 Flue Gas Analysers

 

[Riley]

Yes that would work. It’s working on the assumption that they have a Kane analyser, that they haven’t already spent out on a CPA1 kit and that they don’t just see it as preventative how the kitchen fitter has cut the cupboard. I wouldn’t buy a flexible tester just for one job

 

[Riley]

It would strike me as the easiest option to just cut out more of the cupboard top or completely remove and create a removable top if it’s important that it must be covered

 

[SimonG]

Multi tool. Job sorted.

 

[townfanjon]

^^^^^ thats what I would do.
Are you going a bit over the top sourcing flexi probes for the heating engineer , just warn him prior to a service or sort the cupboard .

 

[rpm]

Also you say you have a vokera yet the flue is clamped with a Vaillant clamp??? And the test points are common sense really

Only if you have the faintest experience does it become common sense.

 

[quality]

Indeed! Although to be fair, the manufacturer's instructions don't refer to a space required in front of part of the flue.

There will be a dimension for above the boiler and yours clearly does not meet that requirement. Is this the same install you were asking about last month?

 

[Riley]

Only if you have the faintest experience does it become common sense.

True enough mate but the fact that they’re asking means they understand.

 

[Scott_D]

Vaillant been out and voided the warranty?
Is it fitted under a worktop?
Can the trap be removed? Valves accessed?

 

[Riley]

Vaillant been out and voided the warranty?
Is it fitted under a worktop?
Can the trap be removed? Valves accessed?

Bloody hell yes you’re right. It is isn’t it. It’s not a cupboard. I was too focussed on the flue

 

[firemant]

There is a joint behind the angled boxing.? Is boxing removable?

 

[Riley]

Think it’s a single vertical straight out the roof mate

 

[Gazzzz101]

Also if a flue is in a void or boxing it needs inspection hatches and should be in line with tb008.