Mushroom vent

[buckers]

My 28yr old Viking cruiser has just had a BSS and the assessor has advised me to change the mushroom vent on the paloma water heater for a aluminium lpg water heater cowl. I have the cowl, I have managed to get the screws out of the mushroom (after unscrewing the top) but I cannot budge the base. Am I right in thinking there's just a seal holding it now & should I hit it with a big hammer, it's impossible to slide anything under it. Help!

[RLWP]

It's probably stuck down with sealant. Hammer your least favourite scraper under it

 

Richard

[Ex- Member]

Possibly a Butyl type sealer, if so it can stick to the extreme and really take some effort to remove. Warming the area can make this much easier to remove, but the Butyl can become very gooey and messy to remove afterwards.

[buckers]

Thanks guys, the mushroom is now off. Just one more question, does anyone know if there's a legal, safe, minimum length the flue has to be before I start cutting it down? Wouldn't want to cut it too short but I also don't want it to look like "Stephenson's Rocket"!

[RLWP]

You are now into one of the famous canal boat compromises. If it is cut down, you have probably deviated from the technical guidance for the boiler and invalidated something. If you leave it too long, you'll bash it off on bridges and keep catching ropes around it

 

Your call, you are the design authority

 

Richard

[buckers]

So be it, ta!

[Chertsey]

Of course this aspect of the BSS is only advisory; the Paloma hadn't killed anyone yet, you may be completely satisfied with your ventilation arrangements, and you could have kept your mushroom ventthat had obviously been doing the job perfectly adequately for years.

 

(Cue the usual reams of 'better safe than sorry', 'you can't put a price on peace of mind' etc hand wringing. Let's just take them as read shall we guys?)