Best Of
Re: Pumping towards?
yes and that is fine. It would be best to have the expansion tank connected at one of the tees above it.
Then you would be pumping away
Is there an air purger under the blanket? Or just a magic trick😃
hot_rod
Re: Do you trust the “pros” in your area?
When criticizing education, make sure you chek you're speling carfuly. 😂
Re: Radiator with no air vent?
If there are vents on some of the radiator there are probably other issues with the system, probably failed open steam traps letting steam in to the returns keeping the radiators from venting through the returns or possibly failed closed vents on the returns themselves (the returns should never have steam in them so the vents on the returns should never close.) The traps that are failed could be the crossover traps between the mains and the returns or some some combination of both. Less likely but possible is a pocket of water trapped in the dry returns. Somewhat more likely is a connection between mains or returns that is supposed to be in a wet return below the water line of the boiler that has become above the water line when the boiler was replaced with a new boiler with a lower water line.
I almost did a clammy there…
mattmia2
Re: Do you trust the “pros” in your area?
Over the years, I've worked with enough contractors to generally know which ones are competent and which are not. There are a lot of really good electricians local to me, but the rest of the trades are a crapshoot at best. The big name outfits tend to have so many employees that what you generally see are the ones who just got tossed into the mix with little to know knowledge on the trade. When I was working commercial, there were thousands of other tradesmen who came and went during that time and while I'll admit that sometimes I didn't belong there either, VERY few of them were somebody you'd want on your team. One job in particular was a remodel of an entire level in a hospital with all new boilers, piping, fan coils, heat exchangers, and everything else hydronic. I was a foreman there for about a year and had a total of about 90 pipefitters pass through my crew despite never having more than 15 at one time. The only guy I could trust to do anything without messing it up was a brand new first year apprentice, and even he was one that was late every day. One guy was in his upper 50s and couldn't do anything without having his hand held. I tried for 3 weeks to spoon feed him and answer every silly question, but one day he asked me for the 30th time "what does this symbol mean?" on the print (it was a valve symbol, that everybody knows) and I lost it. "You can't weld, you can't solder, you can't read a tape measure, you can't core drill, you can't climb a ladder, and you can't read a print. What exactly can I use you for?" His response was that he just turned out as a journeyman (following a 5 year apprenticeship) in 2004 so I have to give him a chance to learn. This discussion took place in 2017, so he'd been a pipefitter for ~18 years but needed more time. I'm of the opinion that you're either a tradesman or you're not, and you can't teach someone with no mechanical inclination to be one. Unfortunately many of those people can't do anything else either, so they come to the trades because it pays well and generally allows a lower level of education than say, a white collar job. Even some of my fellow foremen who were in charge of big 7 figure jobs could barely be trusted to cut a thread or sweat a joint, but they were well organized and could adjust the manpower enough to make a schedule work.
Just a few months ago I had a service call on an old WM that was making funny noises and the basement heat wasn't working. The first time homeowner had paid 2 small shops and one big shop to fix it and one of the little guys replaced a relief valve and expansion tank (maybe it needed them but maybe not) and the other two told her the boiler needs to be replaced. It was as simple as a new circulator (noise) and new thermostat (basement) and took me 5 minutes to figure that out. I'm definitely no genius when it comes to service and generally avoid service for that reason, but after seeing the competence levels of other local shops, it's actually scary what people are doing out there.
GroundUp
Re: backflow valve ?
Someone complains if an RPZ or similar is discharging out of the vent? And this is a problem? May I humbly point out that the only time it will do that is if isn't functioning properly and needs servicing or replacement? Preferably yesterday morning?
Don't complain about it. Fix it.
"BTU meter" results for WGO-5 boiler
After more fiddling around, I was able to get my new ultrasonic flow meter working to try to measure the BTU output of one of my Weil McLain WGO-5 boilers. It turns out I ordered the wrong size transducers, which only work on pipe sizes 2" and up, and I had wanted to measure the flow through the 1-1/4" copper supply pipe coming out of the boiler.
But because the 1-1/4" copper enventually transitions into three larger-diameter gravity conversion pipes, I was able to get the meter working on the three larger pipes. So by measuring the flow rates on the three larger pipes, I was able to get a total flow rate.
One interesting thing I found was that the flow rates were not steady through those three larger pipes. The flow tended to fluctuate slowly by +/- 10% or more in all three pipes, never settling down on a fixed rate. But by observing the rates for several minutes on each pipe, I was able to get a range and then take a center "average" flow rate for each. Adding those average together then gets a total average flow rate through the boiler, which turns out to be 10.1 gpm.
I also had temperature data loggers on the supply and return of the boiler, and took a 20-minute steady-state time average delta T, which turned out to be 20.2 degrees.
The combination of the flow meter and the temperature data loggers is, in effect, a BTU meter. Because of the flow fluctuations, these are not highly accurate numbers, but I think the results are ballpark reasonable.
So, multiplying through to get BTU's hour:
10.1 gpm x 20.2 F x 8.3 lb/gal x 60 min/hr = 102,000 BTU/hr (rounded up)
Then this is the measured boiler BTU output rate in the water supply. At a known oil input rate of 165,000 BTU/hr, that's a net output into water of 102,000/165,000 = 62 %.
So here's the breakdown of where the 165,000 BTU total input goes. 25% is lost in combustion (18% measured dry gas loss, plus 7% assumed latent heat of vapor loss. 62% goes into heating the water. The remaining 13% is absorbed by the boiler thermal mass as it heats up (I figure this is about 10%) and radiated as jacket loss into the basement (I figure this is about 3%).
I have a thermal post-purge set up to keep the circulator running until the water temp drops back to 90 degrees, so we should be getting some or most of that 10% absorbed by the boiler thermal mass back. Also, the basement is useful space (my shop plus laundry area) so I count the 3% jacket loss as useful heat.
So if we recover half of the 10% boiler BTU absorption in post-purge, that's 5% recovered, plus the 3% jacket loss which I count as useful heat for my shop. Adding those to the 62% measured BTU's leaving the boiler as hot water, that puts us right at 70% system efficiency.
Now, at @EdTheHeaterMan 's advice, I'm going to take this new information plus $4.50 to Starbucks and buy myself a cup of coffee. 😀
jesmed1
