Tecky-Talk

While fire rope answers the question, remember that there must be NO metal-to-metal contact between the flue pipe and the roof collar (as is found on many new boats where the builder couldn't be bothered to ensure concentric entry by use of a suitably 'joggled' flue pipe). That said, you may be wondering why no metal-to-metal contact between flue pipe and collar is essential - simple answer - this metal-to-metal contact forms a heat-soak at the contact point which is turn causes the rising (hot) flue gases to stagnate (cool) and roll back down the flue thereby inhibiting the evacuation of CO to the outside world ...

Gregg ... Simple answer - CSST (TRACPIPE) isn't cleared for use in the marine environment (vibration etc) ... If you want further info, please PM me TT

Mike ... On the understanding that you are CCLP1B qualified, possess (cuurent) copies of BS EN ISO 10239 and PD 5482-3 (and install to them), you'll understand that these documents provide clear guidance on the requirements for IWH installation aboard small craft (both new intallations and 'like-for-like' replacements) in a manner that supplements the baseline requirements of L56...

(L56 Reg 30) To be sure we're both on the 'same page', I'm not saying a MORCO on an in-scope boat is illegal, I'm saying tha you can't install a non-balanced flue IWH on a boat that is live-aboard (and has never had an IWH previously fitted). If the subject of this thread relates to the replacement / re-siting of an existing IWH (regardless of make), a non balanced flue IWH can be fitted providing the replacement is like-for-like - ie : RINNAI REU - 85E out dictates replacement by a RINNAI REU-85E ...

Hi ... As a marine GSR installer, I'd like to point out that the responses so far have failed to mention the need for an essential flue component for the MORCO - an adapter collar that sits on top of the draught diverter and provides a correctly dimensioned fit for the inner flue pipe (see image below). If you are using a 'universal' flue - ie: one with an aluminium inner and a white enamelled outer, the inner (hot) tube goes up inside roof mounted terminal (tight fit) - see images below: Note that the white enamelled tube is simply there to ensure the inner (hot) flue tube DOES NOT come into contact withe the cabin roof lining of the craft. This outer tube need to be trimmed to about 20mm above the external roof line - if it's longer the roof terminal shroud will not fit over it. The inner tube should be trimmed to the same length as the roof terminal shroud (see picture). If you have followed me so far there's one more REALLY important issue to address - the flue pipe MUST BE VERTICAL ! If your roof is heavily cambered, the skirt on the roof terminal shroud cannot be massaged to fit - you must have an adaptor collar manufactured (see picture below) to ensure the flue is VERTICAL - if it isn't, the inner tube wont sit squarely on the heater's draught diverter and flue gasses WILL leak out into the gap between the inner and outer tubes - the flue will not operate efficiently and you may be at risk from CO poisoning ... If you are fitting a flue to a MORCO, please seek the help of a competent (registered) installer. PS: If you are a live aboard, your boat is in-scope of UK Gas Regulations. If you are not Gas Safe Registered, you CANNOT do ANY LPG work on your craft. So, if you are contemplating fitting a 'standard' MORCO IWH to your boat (ie not replacing one that has died) such an installation is ILLEGAL and you won't find a GSR installer willing to do the work. If it is a new fit on your boat, the IWH MUST have a balanced flue (ie: a room-sealed appliance which draws its combustion air from outside NOT from the cabin). The ONLY boat compatible appliance is the MORCO F11 (which needs 240v to power the flue fan).

Nationwide Alliance of Boat Surveyors & Examiners LLP (NABSE) www.nabse.co.uk A website which caters for the needs of NABSE LLP Partners (Small Craft Surveyors / BSS Examiners / (Marine)Gas Safe Registered Engineers)and boat owners. The Nationwide Alliance of Boat Surveyors & Examiners is a Limited Liability Partnership that was formed to ensure that UK boat owners receive the very best of in-scope professional services. The partnership comprises Small Craft Surveyors, Boat Safety Scheme Examiners and (Marine) Gas Safe Registered engineers who are dedicated to delivering the Alliance’s motto: “The professional link between boaters and boats ...” In addition to providing the usual range of services delivered by Small Craft Surveyors, Boat Safety Scheme Examiners and (Marine) Gas Safe Registered engineers, the Partnership, via its website, also hosts a Boaters' Forum where boat owners can engage in open debate with professional surveyors and examiners and find the answers to a wide range of boat-related issues.