Gene Cafe Heater Replacement - Sealing The Heater Box

This is mainly educated guesswork, based on observation of the inside of the Gene Cafe Roaster

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I know that in the past there have been pre March 07 manufacture Gene Cafes which for various reasons will have had one or more heater replacements, after examination of my own and others March 07 and later Gene cafes, I have some comments regarding heater replacement, that may prove useful to anyone who has to complete this task.

I have taken the liberty of reproducing a small photo from Genesis own service guide and you can clearly see the application of Silicone sealant where the Heater Box attaches to the main inlet vent (they call it the damper out assembly, but it's not it's the damper in assembly). I have also noticed this sealant used in my own and others Gene Cafe roasters. Unfortunately the specification of this sealant is not given (Genesis haave since responded), but there are a few broad types types of heat resistant silicon sealant adhesive on the Market…from 250C to 300C and1200C (there are a few others that are good to 275 and then brief periods up to 300C).

The article that follows is educated guesswork and you undertake any repairs at your own risk.

It is clear from the service manual that a silicon sealant is used….my best "educated guesswork" follows


I think this is to reduce the risk of hot air "leaking" into the sensitive electronics and other more heat sensitive internal components of the roaster. It ensures that hot air is only directed to those parts of the roaster specifically designed to take it. When the heating element is replaced, the existing silicon may be enough to maintain this "seal". If, however the seal is not good and a small leak is introduced, then there is a higher possibility that other internal components could fail after a heater box replacement (it could also be the reason for some of the odd failures I heard about prior to March 07).

The question is which high temperature sealant should one use, personally I think 1200C is probably unnecessary and would be looking at a high temperature Silicone sealant good to 300C.

There are a number of products I found that seem good for the task and here is the specsheet for Everflex Heat Mate. This can currently be bought from e-bay sellers for around £10 including delivery (310ml cartridge for use in a caulking gun). It is a shame that the product is sold in such large quantities as you only need a small amount and with a limited shelf life of around 12 months unopened and probably less after opening, it's a bit wasteful. However see the footnote below, after I received a reply from Genesis. if you look up the product specs for the 3140-RTV as i did, you may feel happier using some alternative and much cheaper products. A search on e-bay for RTV sealant, can produce some nice product in the £5-7 range, the key things you are looking for is temperature resistance to round 250C, it should be a sealant/adhesive, but most of these products will fulfil that function as they are inherently sticky anyway.

RTV stands for Room Temperature Vulcanising Rubber (silicone's tend to fall into this category). Avoid 2 pack mixed products as some of these can begin to flow (become liquid) under prolonged heat conditions. Remember the shelf life of RTV's tends to be around 12-15 months if unopened, and only a few months after opening.

Here is the inside of a friends Gene Cafe to put the above picture in perspective (click to enlarge)


I will try and check the specifications of the product that Genesis use and if they reply, will update this article.1


I would imagine you can replace the heating element without using any sealant and hope that the existing sealant maintains the seal (which it might). However, it is possible that there could be a small leak, which may or not may damage other internal components within the roaster. this could mean that the failure rate (or MBTF) of such a roaster could be higher than one where new HT silicone is used.

  1. You might need a sealant that withstands temperatures higher than 300C (my best guess is that you would not)
  2. I think it's a decision best made when you actually come to replace your heating element, based on your assessment of how good the seal is and whether the purchase of an appropriate HT Silicone adhesive sealant is necessary.