Glow-worm 30 CXi Flue Sampling Point Cap 0020031334

I went to issue a Landlord's Gas Safety Certificate at a property which had a Glow-worm 30 CXi fitted. I stripped down the boiler for a service and as I did so noticed that the cap which usually covers the flue probe hole was sitting on top of the boiler. At first I assumed that the previous engineer had forgot to replace it. I tried to thread the cap back on but it was not screwing on. Looking at the plastic cap it had started to degrade, the threads were worn away and the condition of the plastic was deteriorating. The thread on the flue which the cap screws onto looked to be in good condition.

The boiler is the older version which had an earlier Vaillant flue terminal. The flue sampling point is on the bend of the elbow unlike the equivalent Vallaint combination boiler which has a separate flue adaptor on top of the boiler with an inner and outer flue sampling point and different caps with different threads.

I asked in Parts Center regarding this part and was given a retail price of £53+VAT and told they only come in packs of five. The part number is 0020031334. The going rate appears to be around £40+VAT online, but our price at Parts Center was £30.10+VAT which is still a lot for 5 plastic caps and washers. For a critical safety item to have failed at this boilers age is not good and these new ones I hope are better made. There is a Technical Bulletin which covers this issue, number 138.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.