Whats the best way to heat domestic hot water

[Holmes]

  I wonder how much oil you use with a "cold start" a couple of times a day versus the oil required to keep the water jacket of the furnace warm 24/7?

You could save 50% per day. It may only be 1/2 to 1 gallon but for 60 to 120 days it will add up.  You can put a timer on the 2nd boiler and set it to not run at night time only.  Holmes

[doctorb]

Good suggestions on which I need to act, as the OWB heating season here is only going to last another 6-8 weeks.  Thanks, Holmes, I do appreciate your input.   Docotrb

[ken999]

Doc- Are you plumbed directly into your oil boilers or do you have heat exchangers?

I burn my 2300 once a day, all summer long, and it has enough stored btu's in the 450 gallons of water to do our domestic for 24 hours. Our 2300 is plumbed directly into the water jacket of our indoor boiler, and that has a 37 gal domestic tank on it, heated by the water from the 2300.

[doctorb]

ken999-

I have heat exchangers, in fact, I have a complete set (HWB and DHW) in 2 different basements for two separate systems. 

Your set up is interesting, and after the winter, it would not seem like a lot of work to keep it running once a day.  But my hot water is heated two ways with my system, by my understanding.  It gets heat from the heat exchanger loop for the DHW from the OWB, and its also heated in the DHW boiler jacket by the standard boiler jacket used for HWB.  without being directly plumbed to the DHW jacket, I am not sure that I have that option.

Thanks for your input.  Doctorb

[John Mc]

Doc -

Have you considered Solar Hot Water? There are some decent systems out there where they use a couple solar hot water panels to preheat a holding tank. On sunny days, this preheat tank is hotter than your main hot water tank. Even when partially sunny here in VT in the winter, it will preheat your water at least partway, so you are not refilling your hot water tank from 50˚ water from the well. You keep whatever is heating your domestic hot water now, but it only kicks on when there is not enough sun to stay ahead of your usage.

Plumbing is very simple. You just break into the cold water feed line to your hot water system and feed from the preheat tank. If you have a south-facing roof with decent sun exposure, you can mount the panels on it. Alternatively, you can mount them on a rack near the ground.

There are a number of companies selling pre-packaged systems that are fairly easy to install. Lots of folks "do it yourself", but if you are not comfortable with that, the prepackaged nature of the system makes it a snap for any plumber to hook up the system.

Here's the link to a supplier of prepackaged systems near me that ships nationwide: http://www.gosunward.com   One of the options I really like is a "timber-frame" like ground mounting rack that can easily by finished into a playhouse, tool shed, chicken coop, etc. I'm debating between that and mounting on the roof of my garage.

Their systems is eligible for a 30% federal tax credit (that's a CREDIT, not just an income deduction). Many states also offer incentives for these renewable energy systems. I'm not sure if MD does or not.

John Mc