Boiler OUT temps

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ulooknatme

Member
Hearth Supporter
Jun 22, 2008
17
so md
Fired up the solo 60 yesterday for the first time. Try'n to figure out what I'm doing right or wrong. Boiler temp went up to 160 and cir came on, this was exciting. Temps climbed up to 185 in the boiler but temps coming out to the thermovar valve was only 155-160. Temp going into boiler with balancing valve set at 45 degrees was 145. Temp of tank storage 68. The first thing that got my attention was the blower shut down after running for 10 min. When this happened I turned stove thermostat to max and closed the bal valve to almost off and brought the boiler return temp down to 120. In a few min the fan kicked back on. Now I thought temps going into boiler should be 140 or above? This is one shortfall of the manual. Not giving normal temps coming and going and what to expect. I also never got chimney temps over 300. I'm doing something wrong but not sure what.
 
Might be air, even with proper bleeding plus air vents, my system, had to burp a few times. I should remember water temps off the top of my head, but I don't. I have the termovar loading valve and it takes 45 minutes before the system starts sending hot water to storage.
Your stack temps seem a little low(where is the probe inserted?) for a solo, but it takes a while, don't expect stack temps to jump right up there. Are you gassifying correctly?
 
With almost the same operating conditions, here is what I experienced with my Tarm Solo 40 on the first firing of the season 10 days ago:
1) tank return to boiler at 68F (1000 gal storage tank)
2) boiler/Termovar output to tank at 168F (it really was 100F differential, varied +/- a little)
3) Termovar/return to boiler at 150F +/- (balancing valve set to maintain minimum 150F boiler return)
4) flow to tank at 2.75 gpm measured with a flowmeter
5) boiler output 137,500 btu (100 x 500 x 2.75)
6) flue stack probe temperature 400-500F, but closer to 500 during most of the burn (with homemade "chain" turbulators)
7) boiler temp, as measured by the thermometer on the Tarm, was about 170F and never climbed higher. I only burned one load of wood, which was not enough to heat the entire storage tank. Tank return to boiler remained at 68F during the entire burn.

If your boiler is shutting down (going into idle phase) at 185-190F, which would be the typical draft fan off point, then hot water is not moving out of the boiler to the system at a rate at least as fast as the boiler is making hot water. I suspect you have an air lock or other blockage on the boiler output side of your plumbing which is preventing the movement of hot water, or you have an air lock at the circ which is preventing the circ from moving water, or the circ is malfunctioning, or some other valve is partially shut. Another possibility is under-sized plumbing/circ (too much pump head) between the boiler and the tank which is causing insufficient water flow. You need to be moving 3-4 gpm to take your full boiler output of 160,000 btu at 100F differential, and as the differential closes you will need to be moving a lot more water.

My typical flue stack probe temperature during gasification will be 400-600F, with the 600F peak at the very highest burn time, 500F during about 2/3 of the burn, and 400F during the balance, with temp dropping as the wood load burns out. My flue takes an immediate 90* from the boiler to vertical, and the probe is about 15" above the 90* in the vertical section (black steel stove pipe).

Check everything out; you should get at least equal or better performance with your Solo 60.
 
Fired her up twice more and did maintain 500* stack temps. (I haven't installed the turbulators yet but do have them) I still cant figure how to get the boiler out temps higher then 160* I have the temp knob maxed out.
When the higher temps finally reached the copper fittings under the two tanks totaling 1400 gal, I sprung a leak and now am in the process of dumping out all the hot water.
(just for info my pump is a 0013 taco and all my plumbing is 1-1/2'' copper. Distance to house is 160'. Surprisingly, the temp drop from shop to house when being delivered at 155* is less then 1 degree.)
 
On a rough calculation, you may be getting 20-25 gpm with 1-1/2" pipe and a Taco 0013. At that flow rate, it is not surprising that you are not getting more than 160F out of your boiler from tank storage to boiler at 68F. The Termovar is doing its job and opening only enough to ensure that the boiler is staying hot (150-160F) and the balance of the flow is above the btu capacity of the Solo 60. When the return water from storage starts to go up, you will start to see boiler output temp go up, but probably won't see this until temp of water from storage gets above 140F or so.

The Solo 60 is rated at 200,000 btu. My guess is that average output over a burn is more likely 60-80% of rated output. At delta-T=20, a flow of 20 gpm will move 200,000 btu. You certainly have an abundance of circ capacity.
 
It's also worth noting that there is a "break-in" period for these boilers. One thing that happens for your first few fires is the removal of moisture from your refractories. I wouldn't be concerned until you get your tanks up to temp and then see how she rolls...
 
Went and installed a tall 40 gal hot water heater beside the expansion tanks.(striped off the sheet metal and insulation) Cranked up the temp of the pressurized tanks to 160* and the hot water heater never went above room temp. I'm now hooked up to the main system of the house and hopefully will never buy any more propane. (I averaged 3000 bucks a year) Tomorrow I buy 2x4's to build a wall around the tanks and think I'll blow in insulation. (do you guys wrap aluminum foil around the tanks first to stop the radiant heat?)
 
ulooknatme said:
Went and installed a tall 40 gal hot water heater beside the expansion tanks.(striped off the sheet metal and insulation) Cranked up the temp of the pressurized tanks to 160* and the hot water heater never went above room temp. I'm now hooked up to the main system of the house and hopefully will never buy any more propane. (I averaged 3000 bucks a year) Tomorrow I buy 2x4's to build a wall around the tanks and think I'll blow in insulation. (do you guys wrap aluminum foil around the tanks first to stop the radiant heat?)

I did not use any foil especially with the blown in cellulose as this stuff is extremely dusty and it will cover the foil quickly.
 
One property of reflective foils that the sales people never mention is that the reflective 'magic' relies on an air space and clean foil surface to work. If it is laid up against the surface it is intended to insulate or gets dusty it doesn't have much effect anymore.
 
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