Who thought hot water could be so complicated huh? Iam doing a similar set up right now except we are using a heat pump water heater as the main/back up. Highly recommend you look into them if you have the appropriate climate and space. Be aware that the Desuperheaters usually only produce measurable hot water during the cooling cycle which could be seldom depending on climate and efficiency of the building envelope. If you go tankless (personally not a fan in most situations) be sure its capable of handling pre-heated water. Holding or Buffering tank is a good idea no matter what the back up tank is. A cheap electric storage without the power hooked up is fine. I would add insulation to the tank(s) and absolutely insulate ALL hot water lines as much as possible. Obviously, energy use matters to you so be very careful with how you set up a circulating pump. A manual or occupancy switch located in the farthest bathroom is the best bet. Continuous circulating pumps could easily end up burning more energy than what youre saving with the Geo. I would also recommend monitoring the energy use of the circulating pump for the Geo. COPs usually ignore this part of the equation. Check out the below link and do someother keyword searches. Here is a link that might be useful: GBA link geo + tank Q &A

trudy is there a basement - or just slab? do you have any idea how they plumbed over to the master suite? do you know the diameter of the pipe they used? did they run one large feeder (probably either 1 inch or 3/4 inch pipe) and then branch off of that with 1/2 inch pipe to feed the sinks and shower? how far away is the hot water tank from the master bath? this info would help in pump selection. I have pretty much the same problem. My house is 100 feet wide with master on main level. we put hot water tankless in basement under master suite side but kitchen and 3 other sinks are on the opposite side. having the basement made adding an additional reactrack recirc loop, small electric hot water tank, and pump not to difficult. if you are on a slab, then you will need to use existing pipes to circulate the water. During my research I found a nice little pump system that might work for you - but it depends on your plumbing. my thought is to put the pump under a vanity sink in the master suite - primarily so that it will be easy to provide a power switch or motion sensor switch to control the pump. the concept is that you provide a bridge between your hot and cold water supply tubes (they make a special fitting for this) feeding that sink. The pump sits in this bridge. When the pump is off, the hot water supply flows to hot output of faucet, cold supply flows to cold output of faucet. But when pump is on (faucets are off), the hot supply flows over to the cold water supply. Initially when you turn the pump on in the AM, you are essentially taking cold water (curreently in the hot water line) and moving that into the cold water supply for the sink. This process is drawing hot water up to that sink - no water is running out, just being moved around inside the pipes. this pump system has a built in thermostat you can adjust so the pump will automatically turn off when the hot water you darw up reaches the temp you want. The tstat is critical because it also keeps the hot water you draw up from constantly flowing into the cold water supply because then you would be heating your cold water supply and wasting money. As long as the hot water supply feeding the sink is being supplied via a main feeder AND your shower is also tied into that same feeder - then when you turn on the shower (after running the sink pump for 5 minutes or so) the delay for hot water out of the shower should be very short. you can test this right now by manually turning on that bathroom sink (do this in early AM when hot water is cold) and running it until hot water comes out of that sink. then go over to shower and turn on hot water - hot water should flow within a short period of time. if that test works - then this pump system I speak of will work for you. power for the pump would come from a nearby light switch close to the vanity - it could also come from an existing outlet on the wall above the vanity. i can design the pump circuit so you can use either a flip switch or use a motion sensor. do you see any issue with doing that? you would need (or have electrician add) a gang box somewhere near the light switch or outlet above the vanity, run a piece of 14-2 cable from that box to another gang box inside the vanity, and then put an outlet into that lower gang box. the switch or motion sensor goes into the new box above the vanity, the pump plugs into the outlet below the vanity, power is provided when you flip the switch or motion is detected. do you see any issues with adding the wire or these gang boxes? this type of pump system will not cost much to run and actually saves water. most people with this problem just run their shower for 5 minutes, dumping good water down the drain waiting for hot water to flow. This system just moves water around in the pipes, no water wasted. The delta cost is literally the cost to run the pump for 5-7 minutes per day (or eveythime you use the shower). If this can work for you, the cost to install is not too bad. I think the pump system ran around 175 dollars and then you need to pay an electrician to add the switched outlet - maybe another 200 or so. If DH is handy, then cost is less.

Must be an older home that used cast iron or steel pipes leftover from the gravity heat days perhaps, converted steam or an old time plumber. The boiler will have a pressure reducing valve to keep water in the boiler typically in the 12-15 lb range, cold. It will expand as heated thus; there most likely is an expansion tank too. As far as antifreeze, most often use in radiant systems where the tube is buried and if frozen and breaks difficult to access. Antifreeze can be used in your system, NEVER AUTO ANTIFREEZE, soNon-Toxic Hydronic antifreeze is used in about a 30% concentration offering freeze protection to about -10 and burst protection to about -50. Most antifreezes contain corrosion inhibiters and if maintained prolong seals, pumps, piping and boiler however antifreeze is also a insulator and affect heats transmission as much as 10%.

I installed it all and plumbed it myself - Not a really difficult job . . . . maybe 3 on a scale of 5 The collector panel was $1K, the tanks were $600 for the pair, the circulator pump was $100, the differential controller was $200 and about another $300 for copper piping, valves, flowmeter and an analog temp guage. $2200 for the total system, give or take $100. We had no hot water heater to begin with, so we would have had to spend $300 anyway, so take away the $300 and the $400 in Tax rebates and the system actually cost us $1500 - I got $300 off my federal income tax and another $100 from the state My 'break even point' is about 3 to 4 years - It would be higher if I had paid another $1500 to $2K for a professional installation We're remodeling an old farmhouse, so we've never lived here with anything but the solar heat but the tag on the side of one of the water heaters says it costs $400 per year to run - It's a very high efficiency unit with 3 inches of polyfoam insulation, so a lesser water heater would cost more to operate. $500 to $600 per year is probably an average cost for domestic water heating per year for a family of four I REALLY don't understand why there isn't a larger push from the government on solar water heating. Unlike solar electric, or hybrid cars, this technology is pretty well perfected right now and the payback is much shorter than for just about any other 'green' energy source. It can be used in most places in the United States. The outside temp isn't a big factor in how well it works . . . . it depends more on how many sunny days you have If more houses had solar domestic hot water systems, we could make a huge dent in the total energy use of the country and just think of how much less fossil fuel we would consume Don