Help for weekend house

[ncohen]

I have a 2,000 square foot two-story home in upstate NY with baseboards and two zones. It is used only on the weekends. I'm planning to switch out an old oil-fired boiler and local contractors have suggested either Energy Kinetics 2000 or Buderus G115ws with an indirect hot water tank. My question is whether an indirect-fired hot water tank makes sense given that we only use the house on the weekends, and can otherwise shut the boiler down over the summer. Should I install a separate (propane?) water heater and just use the boiler for the baseboards? And given the two brands is one preferable to the other?

Another alternative is an on-demand propane boiler/water heater. Should I consider this as an option?

[Tom Sawyer]

I don't think that the indirect makes a lot of sense at this point but maybe in the future if you rent it out or decide to live there it might, but you can always do that then. Stay away from propane, its very expensive and look into the Buderus G115BE. You get a tax credit on it and it is one impressive piece of equipment.

[jadnashua]

Modern mod-con boilers do NOT maintain a constant temperature, they only fire on demand - they are designed to work just fine on cold starts which would destroy most older boilers. So, what's worse, a propane fired WH that's maybe 55-60% efficient or a boiler designed to be over 90% efficient. A good indirect WH tank may only lose 1/4-degree per hour in a typical situation, and the boiler may only fire once while everyone is taking their morning showers. A typical WH will have bigger standby losses, and fire more frequently at lower efficiency. Older boilers that had to maintain internal temp constantly are another matter...they don't make a lot of sense to keep running all summer. Most utilities will give a fairly substantial rebate on a HE boiler and indirect, offsetting the higher inital costs as well. Plus, the indirect will heat up MUCH faster than a stand-alone tank, and provide more hot water per size as well. Energy costs aren't going down...

[tk03]

The standby loses on indirects are tested with no thermal flow out of the tank. When most tanks are installed in the field they have no thermal trap so the standby loses are much higher. Most mod/cons are set to heat the IWH with 180f water temp from the boiler. If left there the boiler efficiency is about 85-86%. If the temp is lowered the efficiency will increase but will take longer for the tank to heat.
The federal rebates and most state rebates are gone but there may be a few utility rebates around. Check with your local utility to see if they offer one.

[jadnashua]

Local utilities here are still giving as much as $1400 rebate on a HE boiler/indirect...depends on your local company. Check, then decide which way to go.