Best Of
Re: Explain This Relay!
My guess is similar to @mattmia2
I would guess they went to 1 stat for whatever reason so the stat would open both valves and pull in the relay coil. The relay contacts would act as the end switch and fire the boiler. Not exactly right but I guess it works.
The boiler and circ shouldn't run until the valves open but with no valve end switches(s) it can't be done
Re: Mono flow system upgrade
I assume you're replacing what you have for radiation and not altering the basement piping except to connect the new baseboards. If that's the case, you should be fine. Put bleeders on the return side. You may not get as much heat out of standard baseboard as the convectors put out as the elements are smaller unless you extend the baseboard length.
Re: Pressuretrols and Gauges
you can disconnect one of the t-stat wires at the boiler and see if it still happens. if the anticipator setting in the t-stat is way off it could turn iff the boiler before you really get any heat from the house to the t-stat.
mattmia2
Re: Pressuretrols and Gauges
Test equipment like a multi-meter is the most common way to perform testing, but that is not the only way. If you can carefully disconnect one wire at the thermostat and see if the boiler starts, you may have to wait a while. While disconnecting the one wire look for dilapidated insulation causing the thermostat wires to touch and bypass the thermostat, it does not take much.
109A_5
Re: In imminent danger of house freezing (Minnesota) - solutions?
If you are going to winterize, and I believe you should as mentioned above, have the meter removed by your water company and have the entire house's piping system pumped with non-toxic/recreational vehicle (RV) anti-freeze. All low points must be evacuated of water, including any appliances, ice maker, refrigerator etc.
And then pour antifreeze in all toilet tanks, toilet bowls, and any "P" traps that would hold water. This will save the house till warm weather returns and a replacement can be installed.
Intplm.
Re: Mystery 'U's\dips where Steam Mains meet Dry Returns, (and Water Hammer)
If those are Trane convectors, they probably have orifices cast into them. Otherwise, the traps may be in the basement.
Re: steam radiators are hissing loudly and spraying hot water/steam
On your comment 1. There is nothing in a radiator, It is a hollow chunk of cast iron — nothing more, nothing less.
If vents are hissing, there are really only two possibilities: they are defective or the pressure is too high. And, I might add, if the pressure is too high the vents will be defective very quickly.
Which goes to your comments 2 and 3. You are presuming that sincee the system works well the problem isn't with the pressuretrol or the pigtail. I beg to differ. Steam is, in some ways, oddly forgiving — and excess pressure is one of those ways. While it creates all manor of problems, what it does not usually do is keep the system from heating. Add to this that "the gauge does move" — if it is the normal 0 to 30 psig gauge, that almost certainly means the pressure is too high.
Re: A2W heat pump as primer for 4 bank hydrothermo ( 864,000 btu )
Thank you. It wouldn't surprise me that the heating system is oversized. Why would someone spend extra time to properly size a system and make less money off the deal. Throw 4x the gear at the solution, never have a not enough heat call back and make 4x the markup.
I'll review the heat loss article. The building is going to be modeled in CAD soon so I might be able to leverage that and throw it into LoopCAD and do the heat loss calculations there without too much work.
At this stage I'd just like a quick easy win. Throw something residential in for pre-heating if possible and save 10% pay back in 10-20 years is fine. Eventually the boiler needs replacement and it looks like high efficiency gas is likely to be the best choice given the heat loads. I had one quote just for the boiler of $52,000 and that is without installation. We'll likely run to failure for the existing heat plant - really I think until one of the 4 units dies I won't be serious about putting the work in to figure out a replacement plan. Yearly gas bill is ~$26,000.
My napkin numbers.
Going from the 80% to a 96% ( assume you only get 90% ) would save $2000 a year ( some of that gas is for the domestic ). $52k for the boiler assume optimistically $26k for install? would be a 39 year pay back which is too long. I like mechanicals but right now seems like doing things to decrease heat loss are going to be the biggest bang for buck.
walnut
Re: DIY Boiler Monitor Project -- Useful?
Great info! Clever data collection methods
6 minute run times are fairly short. Probably mild season loads?
With run time and off time.
6 minutes on, 11 minutes off, total elapsed time= 17 minutes
6/17= .352 run fraction 35.2%
So running about 80% cycle efficiency
I'd like to see the return up around 140F at shutdown. If you could get a CO2 reading you could determine if the boiler is still condensing when it shuts off. Or the flue is still sweating?
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With a cast boiler you might bump the min. on the tekmar. Are you using a return sensor? You are limited on reset temperatures with a cast boiler might not do a wide reset with a cast boiler
Graphs from Modern Hydronic Heating & Cooling 4th edition
hot_rod