Why do you get in the one recipe of boiler 2 as a product additionally 4 heat pipe 2? With the mod ReverseFactory it is then possible to easily produce aluminum and invar. Even if you have never mined them.

Input:
5 stones
4 iron plates
40 copper plates
29 steel

Output possible with ReverseFactory:
1 boiler 2

4 heat pipes in the ReverseFactory:
40 aluminum plates
20 Invar plates

... what?
Boiler 2 shouldn't have heat pipes in it.
You can turn Boiler 3 into a Heat Exchanger...

It sounds like there's a bad mod interaction here somewhere.

Here is a screenshot. In another recipe you get 2 Steel pipes in addition.
https://imgur.com/lKkqZkw

I made a bunch of changes to the heat related entities last version. Obviously missed adjusting some of the conversion recipes, oops! I'll get that fixed.

https://github.com/modded-factorio/bobsmods/issues/115