Alpha CB28 Pressure relief valve removal

[IanNCL]

I have read and sorted the problem with my boiler's high pressure, by pumping up pressure of the expansion vessel. I am left with a leaking relief valve which I intend to replace. However on my Alpha CB28 the outlet stub of the PRV comes down through a steel plate which is effectivly the bottom chassis of the boiler. This looks like it will prevent me from unscrewing the PRV through 360deg.s to remove it unless I remove a lot of other valves too. Can anyone advise please. Is it an involved job to remove and replace the PRV on this model?

Also I was planning to buy a spare from somewhere like Combiboilerspares.com do I have to be a registered trade person to do that. I am not a trade plummer but have done many DIY jobs in the past so although confident, should I be tackling this or refering to a qualified Boiler engineer for this level of work?

Any advice much appreciated,
Ian

 

[nickso]

just remove the plastic bit from the brass housing, clean up the brass seat inside and screw the new plastic bit back in.