Hot water recycle time question.

[Bugzapper]

I'm sure I'll find out soon enough, but I have a question about recycling time. I have a Central Boiler with 185 gallon tank. With their DHW heat exchanger and 180' water, how long should I figure to heat up a 40 gal primary and a 30 gal. tempering tank with boiler water at 180'? It seems slower than I had hoped. Definately slower than the LP.
Will it help to insulate the exchanger? Do you folks insulate the boiler runs inside the house?

JB

 

[Duetech]

My boiler lines are insulated everywhere they go. There is an insulated sidearm heat exchanger on the side of my dhw propane water heater. I use a tempering valve to prevent scorching but I usually have usable hot water in an hour and a half. It's not as fast as propane but it is much less expensive and worth the wait.