Hot water cylinder spray foam for gaps

[JamieH]

Not an essential issue but I'm considering replacing the bulky cylinder thermostat tied round the hot water cylinder with a Honeywell version.

The cylinder is foam insulated so the smaller dimensions of the Honeywell thermostat would leave gaps in the foam of a good few centimetres.

Is there a specific spray can foam type which would be safe to use for filling in the gaps on the hot water cylinder?

Thanks.

 

[oilhead]

Polystyrene packaging cut to fit would suffice.

 

[AdrianUK]

I can't tell you which type of spray foam to use, but I can tell you, around 10 yrs or so ago, I tried to "repair" damage to the foam insulation on our hot water cylinder using a product from a certain retailer that carries a product range that suggests its 'simple & straight forward'

This seemed to go well initially but over the next few years the foam repair turned black & started to crumble. I can only assume that it didn't like the continuous heat from the cylinder. I ended up scraping it all off & have never tried to replace it.

 

[SFK]

For the price of the can of foam, buy a cylinder lagging jacket and increase the overall insulation.

https://www.google.com/search?q=cylinder+lagging+jacket