Testing A Steam Boiler Probe-Type Low Water Cut Off (LWCO)

[@jfrancis98]

I could listen to you talk boilers all day. Thank you for sharing.

[@gordonschweizer5154]

You are most kind.

[@matthewbecker3674]

Fantastic image quality! It really brings out the hues in that muddy water. Curious, does anything seem odd with that water heater venting strategy? I usually see Y-collectors that merge together, but never a right angle. Worried that with the lower-btu appliance not upstream of the boiler, it might result in backdrafting, or even vice-versa.

[@gordonschweizer5154]

That might be AI adding those nice hues, I don't know lol. As this chimney was originally designed to pull a lot of air through a big pile of burning rocks, I think it works ok even with that admittedly funky tee.

[@Romulan112]

Hello. I have a Triangle Tube PE110 boiler. I am getting error code B 30, which means: High Temperature Limit, Boiler Supply and Return Temperature Differential is Greater than 72 Degrees. Its right after it fires up. Start it up, hits this error code less than 1-2 mins. The boiler then toggles between this B 30 code and a 9 144 which means blocked. Any ideas?

[@gordonschweizer5154]

@@Romulan112 I am sorry, but I have never worked on a Triangle tube boiler

[@captainwho1]

I was a bit negligent when it comes to annually cleaning the probe for my CycleGard CG400-2090 installed in 2007. Meaning I don't think I ever did it lol. I did drop the water down a couple times to make sure the boiler shut off but not for a couple years or so. I know! Anyways I want to say that the Hydrolevel instructions are remiss in the respect that they suggest that deposits on the probe would cause it to get an amber light when water level is actually OK and that never happened to me. I guess that would be for mineral deposits. Well they should mention that iron oxide deposits will be conductive and that is what happened to mine. Fortunately I caught it before my boiler had any possible accidents that would've destroyed it. The probe measures the same resistance whether it is in the boiler water or it is out of it (but still wet). A brand new probe and an older clean one absolutely do not do that. Pretty negligent on the part of whoever wrote the Installation and Operation manual. The new probe seems to be improved in that it has some sort of non stick coating over the ceramic that feels like either polyethylene or teflon.

[@gordonschweizer5154]

Hydrolevel has had problems with their probes down the years, almost all of the issues due to the ceramic failing in one way or other. Sometimes, a small crack in the ceramic will let water in, shorting the probe to "ground" (the brass), and tricking the electronics that there is water in the boiler when there is not. The probe will work when you test it cold, but when you test the LWCO while the boiler is running, that's when most of the failures come to light.

[@captainwho1]

@@gordonschweizer5154 Thanks. I will do baseline resistance checks on the new submerged probe both hot and cold and post the value on the boiler so that I will be prompted to re-check annually. Edit - checked the resistance hot right after a boiler cycle ended and it is like measuring the resistance of a capacitor, where the measured value rises as the capacitor charges up (I guess) so I decided to take several readings after 10 secs. and got a range of 7.3 to 7.6 kOhms so that will be my baseline for the future.

[@jazzcornertv]

Would you recommend replacing the probe after 5 - 6 yrs depending on the water quality in your area. Hard water has shown great potential do damaging everything in site. It is not a cheap part.

[@gordonschweizer5154]

@@jazzcornertv Probe manufacturers recommend pulling, checking & cleaning the probe yearly. They also recommend replacing the probe every ten years.

[@gordonschweizer5154]

@@jazzcornertv A probe might not be a cheap part, but it is cheaper than a new boiler.

[@jazzcornertv]

@@gordonschweizer5154 You have inspired me to contact my boiler co. In NJ the areas with hard water will encounter damage. My boiler is under warranty and they do winter pm, but skip the Low Water Cut Off probe inspection and they don't volunteer to suggest either. Thanks for all your help.

[@patrickwelch620]

How many gallons of make up water is acceptable for an sgo3 or sgo4?

[@gordonschweizer5154]

I assume you are referring to the numbers displayed on a VXT-120. Those numbers should be in the single digits in an ideal system

[@patrickwelch620]

@@gordonschweizer5154 thanks very much. That's what I thought. You mean per heating season right?

[@gordonschweizer5154]

@@patrickwelch620 Yes. The numbers signify the amount of water in gallons lost, more or less Fresh make-up water brings in dissolved oxygen and that rusts out the boiler.

[@patrickwelch620]

@@gordonschweizer5154 Thanks very much. My old sgo used 23g in a month till I switched over to wood for the rest of the season. No leaky valves and no make up water was used for the rest of the season while the boiler wasn't used. Sight glass is still at the same level as back in early Dec. Pressure never went above .5psi (I have a 3psi gauge). Funny I never saw the steam coming out of the chimney like I was told I should see though...

[@scottk0623]

Nice job. What did you get for a camera?

[@gordonschweizer5154]

Thanks! A new Google Pixel phone.