indirect h/w on Ask This Old House episode

kk_2

Did anybody see the Ask This Old House epsiode on Saturday (WGBH in Boston)? Someone wrote in complaining about the hot water being too hot in a downstairs bathtub, and there not being enough hot water to fill up a big upstairs bathtub.

They went to the house, and the guy (Richard?) spent all of about 10 seconds (at least on air) looking at the oil fired boiler that heated the house and pronounced that the homeowner needed to shell out $3000 for him to install an 80 gallon indirect tank, and that the current tankless system was a terrible way to generate hot water since the boiler needed to stay hot all the time.

He proclaimed that with the indirect, the boiler would only need to run when the indirect tank called for heat.

My question - no attention was given to what kind of boiler the existing unit was - I didn't notice if it was cast iron or something low-mass. If it was cast iron, would you really want it completely shutting off except when the indirect called for heat (I'm assuming there is no space heating demand at the moment)? I would think that would make sense only with a low-mass boiler - I know my (very high mass) cast iron boiler takes a long time to get back up to temp if you let it cool off too much.

I just thought the whole segment in the episode was a little too compressed - from reading the letter to visiting the home owner to finishing the install probably took all of 5 minutes. Obviously the details go out the window.

Any comments?

eleft(retired)_3

Ask T O H

That's show business. Did he have more tools than the usual channel lock pliers? High mass 140 low.

al

Steamhead

They really do work that well

and also, they don't lose heat as a standard gas water heater will since there is no flue in the tank. Some indirect makers even offer limited lifetime warranties on their units. We all know we have to read the fine print on these, but when was the last time you heard of a lifetime warranty on a gas water heater?

We've installed these things. They do cost more to buy and to install since there's a lot of repiping to do. Basically you're adding another zone to your boiler. But once they're in, they're great.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Paul Pollets

the boiler

was oil-fired cast iron. The tankless coil could only recover 2gpm against a 10gpm load. An indirect would normally be piped and controlled on a "priority zone", taking precedence over the heating pumps, until the tank is satisfied. In the summertime, the boiiler would only heat the water tank ,on demand. That boiler could easily be up to temperature in 5-7 min, considering it probably contains less than 5gal of water in the jacket. Sized correctly, most 80g indirects will take 12-20 min to recover, depending upon input. The boiler can be high mass, and still have a low water content.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"