Our house has a similar situation. It's 1900 sf, built in the 1890's, has some blown in insulation in the walls (we only know this because we gutted the bathroom and found it - this room will have regular batt insulation in the walls and ceilings), has the original windows but triple track storms. The old oil fired boiler is 199k BTU and our oil bills are completely heinous - we used about $650 worth of oil for the month of December. I can't imagine what our bills would have been for a house 50% larger. Just from a reality check standpoint, there is no way a house the size of ours requires the absolutely largest residential boiler available (there may be some slightly larger but in general, around 200k is as big as they get). Our old boiler does short cycle too, it's loud enough that you can hear it. Even in the dead of winter with single digits at night it cycles on and off. We are probably running somewhere in the 60-70% efficiency range also. Everyone who has quoted for us has universally said "WHOA that's a HUGE boiler for your house." After evaluating all of our options, we are going with a modulating/condensing boiler at about half the capacity (maximum) and putting zones into our house. Right now when it is 68 downstairs, it's about 80 degrees in our bedroom - so at a minimum breaking the house down into different zones for upstairs and downstairs should also help - DH works at home during the day and there is no reason to throw all of that extra heat upstairs when no one is there in order to keep downstairs comfortable. For various reasons we are actually going with more zones than that (the way our system was originally piped makes it extremely easy - labor wise it would be just as much to combine them back into one zone as leave them split - and there is a big temperature difference between the various parts of the house we are splitting off) but you might want to check into whether it is possible given your current piping to separate your 2nd floor from your first into separate zones. Between the zoning and the much more efficient boiler, we hope to slash our energy prices. It's NOT a cheap boiler (the cost of the boiler is more than the cost of your boiler + install) but with our old cast iron radiators with relatively cool return, the condensing part will work great, and with us zoning out our house, the modulating part should work great too (it operates at a much lower BTU if the demand isn't there). It also changes the temperature of the water sent out into the system based on the outside temperature, so if it's 50 degrees outside and we want to maintain say 70 inside, it's not necessarily moving 180-190 degree water through the system, so there is savings there too, especially in the shoulder months. We are switching from oil to gas (it would cost us thousands to replace our oil tanks, the real reason we are replacing the boiler - the oil tanks are not long for this world and because there is no longer outside access to the basement it would be a huge job to get the old ones out in pieces and multiple small new ones in and we decided to put that money into a more energy efficient boiler rather than use the same old boiler and just get new oil tanks) so it will be interesting to see the difference in our energy bills. Anyway it took a ton of research and a bunch of time looking at our system and figuring out what was going on to trace out the various loops we have, but I'm glad we put the time into it. We feel confident with the system we have chosen and hope our house will be far more comfortable and energy efficient for the years to come. Energy prices have nowhere to go but up, unfortunately. We are only planning to do this once so figured we'd do it right the first time. The first couple of contractors wanted to put in either a 200k btu boiler to replace the one we have or a 165kbtu boiler calculated by counting radiator fins. As I said before, some of our radiators have about 3x the capacity actually required for comfort in the room so it's kind of silly to oversize in this way because it's just easier to "replace in kind."

For the boiler, think of a properly sized supply pipe followed by 3 tees in a row. Let's say you use 1 1/4" supply pipe and the tees are 1 1/4 straight through with a branch off of 3/4" or 1". The smaller pipe would feed a loop on each floor. The return line would be just the opposite. The 3 smaller pipes would run into a 1 1/4" return pipe, also using the same T's. On the supply T's, you'd have a zone valve or pump. Some put the pumps on the return line. You don't say where you live, but a coal boiler would be alot cheaper to run than a pellet boiler. Here are some picture links: http://nepacrossroads.com/download/file.php?id=12140&t=1 http://nepacrossroads.com/download/file.php?id=12453&t=1 http://nepacrossroads.com/download/file.php?id=11157&t=1

I did my mother's house a couple of years ago. Single story house with full access to the underside of the floors via the basement. Her subfloor was wood plank on a diagonal with a mix of hardwood and underlayment and linoleum tiles over that, all 1950s original. Maybe 1150 sqft. Did two runs of PEX per 16" oc joist bay. Staple-up. No Al plates. Added foil-faced polyiso under the PEX, tucked up against the staples. To the oil-fired heating system, I needed to take the 180 degree baseboard water down to a more RFH-friendly 120, give or take a few degrees. I used Tekmar controls. A boiler/mixing control. A 4-way mixing valve. An outdoor reset. A couple of thermostats, a couple of temp sensors, A couple of Taco valves and circulation pumps. One manifold. Materials ran somewhere around $2000-$2500 for everything. Wood is roughly R1 per inch. I shoot for three times the R-value below the pex that what is above the pex. Mongo

Hi Alphamale I went with the Navien NCB 240 which was installed at the end of last July. As it turns out it looks like this boiler is insufficient for my needs probably because of the heat demand required for an indoor pool. I'm still not convinced that even without the pool it may still be insufficient in that I run the heat to the pool for only 12 hours per day and when the only heat demand is for the 1,400 sq. feet of house and domestic hot water for 2 people it still has to work hard to get the heat past 70F. Between 7 PM and 7 AM and when it's cold when the pool and house are calling for heat in the morning the house has gone down to 66 F. This is weird because a contractor told me he installed two of the NCB 240s to heat three floors of 10,000 sq. feet each. I spoke to another highly recommended contractor who did an analysis and concluded that the NCB is in sufficient. I have calls into the local Viessmann distributor and another highly recommended contractor for input and recommendations. I am considering using a separate pool heater but it turns out the only one I can install indoors costs $8,000 plus 13% HST plus installation so that could turn into another 10 grand. I can get an outdoor pool heater but I suspect it would cost 5 grand for the heater plus a custom built shelter for it. Another possibility is to get a propane heater insert for the fireplace which would allow more boiler BTUs for the pool. At any rate Dan, depending on your requirements I would recommend converting to propane if only because that's the direction things are going. OIl for heating is quickly going the way of the dinosaur not to mention a big savings in fuel. From my own research if I had it to do over again I would take a close look at the Veissmann and Trinity boilers and there may be others. So far my experience is turning out to be a horror show so be careful.