When installing a new atmospheric water heater are you allowed to just vent into a clay tile lined chimney (6") or are you required to drop a liner. Interior chimney. New chimney... last chimney had a fire. Only thing going into the flue.
it may turn out that the water heater may not be able to create enough heat (Delta T) to create sufficient draft at all times especially when the pilot is burning all by itself.
How tall is the chimney?
I would also run double wall vent connector to the chimney and make it no smaller than 4".
I would tell the customer that there is a possibility that it may not work and that a more insulated vent may need to be run. If it is a straight chimney no bends then you could run a "B" vent up through the existing chimney and make it a chase.
Thank you. This is an odd job. The Insurance company sates that the replacement chimney has to be the same as the old chimney (2 flues) they will not allow them to rebuild a new single flue chimney. Height is 35'. The connector would be only 24". They also want to old water heater to go into the new chimney which will have a few corbels to get around...so B-vent is out. I am installing an electric for now. They may opt for a new tankless model later.