2nd Boiler installation advice

[Dan Victorio]

Hi Everyone,

I'd like to ask some expert advice in installing a 2nd hot oil boiler (400kw) which will be use as a standby to our existing one. Particulary, I'm worried about how we tie in the chimney with the other one as shown in the picture attached. The boiler uses 8" dia. chimney and we need to reduce the size by 3" in order to fit in the existing stack. Will reducing this can cause an adverse effect to the boiler? Please feedback any comments you can see from the photo attached.

Thanks and Regards,
Dan

[RWOLFEJR]

Hi and welcome to the forum.
Maybe contact the manufacturer of the unit and run it by them. You might also find a suggested minimum stack diameter in some sort of installation or operators guide for that particular unit? As you stated... going from 8" to 5" will give you a hole that is 39% of the area of what the unit was apparently designed for. I'm guessing yes on the adverse effect but can't say for certain. Nobody likes to poke a hole in their roof but it really isn't that big a deal. Might want to bite the bullet and hire a professional / insured installer and feel good about the install being as the unit builder had intended...?

Good Luck!!
Bob

[Dan Victorio]

Hi Bob,

Really appreciate your advice. I already feedback my concern to the manufacturer. Hopefully, no much issue for this...

Thanks,
DAn