my 1st water heater install

[mutley racers]

I have been installing a main water heater today and when in the flue box the instructions are quite basic. All they say is screw and tape. But with it came a big rubber, like an oring the size of the flue. Does anyone have any idea where this goes? ( maybe where the joint is on the telescopic flue and then tapr over). And on the elbow that sits on the boiler it has these silicone washers. Now one fell out and I am not sure which way it should go in. It has a tapered side and a flat side. Any ideas guys?

 

[Ermintrude]

Main multi point bf?

 

[mutley racers]

FF it is. I am just reading the instructions now and no mention of the big o'ring and on commissioning it doesn't even ask for a gas rate. Just inlet pressure and burner pressure

 

[Ermintrude]

They are lovely

 

[mutley racers]

Do you know what the big rubber seal is for if you know these

 

[mutley racers]

This it