He posted 3 pictures farther down the string. Yes, this is a basic dumb system. The coil is pretty efficient during the heating season, but quite a waste during the off season.
The pictures show the two pumps as well. They are Taco cartridge pumps so they don't have couplings. There is little to no chance that they would simultaneously break, so I'd say it's likely that the freeze up theory or air bound system is likely. There is no picture of the piping for the two zones, but it's entirely possible that it uses a split system, one with two feeds, that return on a single pipe. If that's the case, one freeze up on the return, takes out both zones.
That system is so inefficient it should be outlawed. My old boiler was like that and I'd be laying in bed on a hot August night and hear the boiler kick on to keep the water hot. Much oil wasted.
My new system uses a stand alone insulated tank and heat exchanger that works as a third zone. It can hold water for a few days with no added heat. My oil use dropped about 40% the past two years.
My savings in oil is paying for the new system. 330 gallons saved at the price today, about $3.60.
I agree. What a stupid system..... However, I could see using the boiler for hot water during the heating season. Then pipe it thru an electric water heater. The electric coils would likely never turn on when the boiler is in use, but once the boiler shuts down in warmer weather, the electric would heat the water.
OR
Have a manual valve system so the boiler would be shut off in Spring and the water would then go to the electric water heater.
(I only say "electric" assuming there is no natural gas or propane available. Otherwise why would he be using oil for heating). But the water heater could use any fuel).
Actually, I used to heat with wood, and I had built a homemade water pre-heater coil that went thru the wood furnace chimney. (A special box on the back of the stove that I had welded, and fit into the chimney). From there the water went to a standard electric water heater. The next summer I built a solar pre-heater. Just a black painted storage tank in a sunny area, with old windows around it. I would have to disconnect that solar one in winter to avoid freezeup, and had to turn some valves to switch over, but it worked and saved quite a bit on the electric bill.
Late fall and early spring were the tough times, because several times the solar part froze up from a sudden weather change. After replacing parts several times, I realized that I was not saving anything, so those times of year I'd just turn valves to run the water directly to the water heater, or thru the coils on the wood furnace, which would either heat or not, depending on whether I built a fire. It took some screwing around and was a pain in the butt during those season change periods, but it did save money.
Unfortunately where I now live I dont heat with wood, and dont have a place near the house that is not shaded by trees for the solar part. The way I see it, the trees cut way down on running the AC in summer, so I save money that way instead.
I'm not familiar with Taco pumps, but they are not on the menu at Taco Bell :)
Actually, both pumps could break if they froze up. It's more likely the pipes froze in the walls, esp any on outside walls. If this is possible, the OP should rent a torpedo heater and run it for awhile to get the house up to around 80deg. Of course there could be unwanted surprises as things thaw out, such as broken pipes. So he should be prepared to shut down the water inlet and pumps.
Not sure why there would be an air-lock just because the boiler was cold, but anything is possible. The only other option is to take some pipes apart on both the outlet and inlet sides and check for flow. I think I'd opt to rent a portable heater first if there is any chance of frozen pipes.
You need valves (even if you have multiple pumps or only one zone) in a system with a tankless coil, because without the valves, the hot water would circulate in the heating system by convection when the boiler was heating water for domestic usage, even if the thermostat was not calling for heat. So despite the two circulator pumps there must be valve(s) in this system.
And the question remains - have the zone control vslves been checked??? I've replaced 4 over the last several years at my friend's place - lack of heat being the symptom, seized valve the cause.
At least 2 happened when the furnace shut down due to a bad thermocouple. (twice) Don't know if there is any cause/effect that could be proven -.
Yes, but not zone valves. Those are called flow check valves. In the newest systems, the flow check is built right into the circulator pump. In the OP's system, one flow check valve can be seen in one of the pictures. It's a green thing with an adjustment knob on top
Yes, but not zone valves. Those are called flow check valves. In the newest systems, the flow check is built right into the circulator pump. In the OP's system, one flow check valve can be seen in one of the pictures. Unlike a zone valve, it has no wires on it, just a check valve that controls the flow rate. It's a green thing with an adjustment knob on top
You need a flow preventer, but not a zone valve. There are a few types, but you can get an idea of what they are here
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They are mechanical and prevent water circulating unless pumped. They can, however, be opened fully to allow for convection heating should a circulator fail. Not as good as having the pump running, but in a pinch, that zone will get some heat.
Probably air in the system. Obviously the OP has no idea of what he has or to fix. Call a professional. Get an explanation from this person as to what you have and how it works. It may be simple to bleed your system or it may be hard/troublesome. Did the system freeze? Never saw an answer...
I also won't quote what configuration of my brother in laws/distant relative/forrmer lover/ system has because IT DOES HELP!
Please post what the resolution is when fixed. Be advised these technicians WILL be very busy.
Yeah, my guess is we'll never hear from him again. It has already been a few cold days so he either fixed it or called a pro and is too embarrassed to tell what happened.
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