LOOKING FOR NEW BOILER

Cokomo

We are replacing a Peerless WB-03 oil fired boiler from 1989. Small 3 zone ranch home.
The issue is we have a one year old Rheem heat pump for dhw. Want to run boiler from November through April (6 mos). Trying to figure out the most sensible way to proceed.
Heat only boiler and wait for Rheem to die and add an indirect? Boiler with coil and turn the heat pump and boiler off and on every 6 months? Partial to yellow boilers. Thanks.

pecmsg

1St get the boiler sized to the heat loss of the structure.
Heat pumps are good above (insert balance point) ?°F, not November - April. This winter in the NE I've used the heat pump 80 - 90% of the time! Much cheaper to operate than the NG.

Jamie Hall

Step one. Find out the heat requirement for your house. There are several ways to do this; the best, in my opinion, is some form of a "Manual J" calculation.

Without that, you have no real idea as to how big a boiler you need.

Then compare your heat loss, room by room (which Manual J gives you) to the radiation in that room. That will tell you what temperature you need to run the boiler at in colder weather, which in turn will tell you whether there is any advantage to a mod/con or whether you'll be just fine with a cheaper and more reliable cast iron boiler.

Then you can pick your boiler.

I'd keep the Rheem from hot water, if it provides enough to keep you happy. An indirect can always be added later to a properly sized heating boiler.

Hot_water_fan

1St get the boiler sized to the heat loss of the structure.
Heat pumps are good above (insert balance point) ?°F, not November - April. This winter in the NE I've used the heat pump 80 - 90% of the time! Much cheaper to operate than the NG.

@pecmsg OP has a heat pump WATER heater.

@Jamie Hall this is an oil boiler. I wonder if the OP wants to add propane/natural gas?

@Cokomo how much oil did you use last year?

Cokomo

We require the smallest boiler made . Also have plenty of heat from mini splits if needed but much prefer the warmth from oil. We used 450 gals each of the last 2 winters. I know its not much oil and we have kept the very reliable Peerless going for as long as we have because it's been so good. However, primary control needed to be replaced last week and we just feel it's time to retire it .

pecmsg

Cokomo said:

We require the smallest boiler made .

Is that what the Manual "J" Said?

Cokomo

Got measured a few years ago and the heat loss  was 27,000. 

Hot_water_fan

Seems like you have it figured out pretty well - oil boilers don't come that small, so the smallest oil boiler will work great. You don't have to assign any DHW production to the boiler. If you still want to, an indirect, coil, or external heat exchanger would all work. The heat pump could pre-heat the domestic hot water prior to the boiler part.

EdTheHeaterMan

Since all you need is 27,000 ish BTU capacity and there are no actual boilers that go that low in Fuel Oil or Gas, then you are looking for the smallest boiler that can be efficiently down-fired. Are you going to stick with Oil Heat? This one has a 0.75 GPH firing rate https://thermodynamicsboiler.com/oil-boilers/low-mass-oil-boiler/
This one has a 0.70 GPH firing rate. https://www.weil-mclain.com/products/wgo-series-4-oil-fired-water-boiler
This one has a 0.65 GPH firing rate https://www.velocityboilerworks.com/product/tobago-twb/
If you are considering the DHW tank as an option for the total job, then I might suggest the System 2000. the control system uses the DHW tank to use up the normally wasted heat that is left over when the thermostat is satisfied. In leu of just letting the unused heated water left in the boiler get transfer to the air going up the chimney, the control logic will operate the pump to the zones or DHW tank until as much of the heat in the boiler is safely transferred to the DHW tank or home radiators. The whole thing is explained on their website. Smallest firing rate is 0.68 GPH. https://energykinetics.com/productgallery-boilers/#section-ek1. Also the boiler design heats up in less than 2 minutes, unlike larger mass boilers that can take over 5 minutes to reach optimal operating temperature. It may cost more up front, but the operating cost over the years will more than pay for that difference.

dko

EdTheHeaterMan said:

https://energykinetics.com/productgallery-boilers/#section-ek1. Also the boiler design heats up in less than 2 minutes, unlike larger mass boilers that can take over 5 minutes to reach optimal operating temperature. It may cost more up front, but the operating cost over the years will more than pay for that difference.

It's also yellow!

Cokomo

Thanks for the responses.  I suppose it’s just a matter of choosing between an Ascent and System 2000 wo tank (for now). 

Roger

Thank your for your questions, @Cokomo , and for everyone's kind comments.
I of course agree that when you're installing a 30+ year lifecycle boiler, savings from efficiency adds up over those years and you're also ready for energy price swings that may come down the pike. For those reasons, I'd recommend the System 2000 (which also comes with unions to install a domestic hot water heat exchanger should the need arise) over the Ascent. System 2000 operation with thermal purge virtually eliminates oversizing losses so you'll run at near peak efficiency even with the smallest loads.
Please let us know if we can help, and also feel free to call us at 908 735-2066.
Best,
Roger

ethicalpaul

> The issue is we have a one year old Rheem heat pump for dhw. Want to run boiler from November through April (6 mos). Trying to figure out the most sensible way to proceed.

You already have the perfect, most efficient setup. You want to remove the most efficient possible way to heat DHW and instead run a boiler during the summer to heat a few gallons of water per day? Madness I say unless you own the oil company.

Edit: Sorry I'm probably confused (it happens LOL). Is this place vacant during the summer?