Safgard Low Water Cutoff - 550, what's the problemm?

[micky]

A friend takes care of a building including a commerical steam boiler. He usually only goes there once a week to make sure the heat is working for the weekend.. The boiler has a low-water cutoff, which seems clearly to be cutting off and stopping the heatf even though tthere is water. The cutoff is at least 30 years old, and it hasn't been cleaned for at least 3 years but maybe 30.

It's a Safgard Low Water Cutoff - 550, made by Hydrolevel.

The place is short of money and he wants to repair it himself. He knows what he's doing but hasn't worked on this exact thing before.

1) I'm wondering how hard it will be to get the probe out, if perhaps it's never been removed in 30 years, or even 10. Any chance he'll need a tap or something to get pieces of metal out of the threads?

OTOH, 2) I'm wondering if all it needs is cleaning the probe. The instructions, which I found online said to do that every year. Ha!. No chance that's happened. (This is Baltimore, where the water is from reservoirs after flltering throug the soil. It's not real hard or real soft.)

3) I'm going to send him back there to look at the installation tee again to make sure it's long enough for the full size probe. Do you think there is any chance that 30 or more years ago there was no model 550SV (which has a short probe) , but since then the probe has gotten longer, and he has to get a 550SV even though

Anything else we should check before ordering a new cutoff?

Thanks.

A picture of one.

If you really want to you can dl the installation, and short operation and troubleshooting instructions, But I think if you know the answers here, you probably know all this.

[Smitty Two]

I'm not so sure that your friend knows what he's doing. This seems to be something that is dead simple to troubleshoot. It should be very easy to test the wiring, control box, etc. independently in order to condemn or eliminate the probe as the source of the problem.

[micky]

You probably know this, but for others, the probe goes into the water and if there is water, the control box will find electrical continuity between the probe, the water, and the metal pipe. Oh, yeah, you're right. Darn, *I* should have thought of that already. We just need to short the probe connections and see if the red light goes out and the boiler comes on.

I was still wondering if a milliohmeter would successfully measure the resistance of the probe/water/pipe connection, instead of just shorting it. I tend to think more about testing than bypassing. It's an occasional but ongoing problem,

He on the other hand is 75 and does a lot of voluteer work like this, for charities and in-laws and friends (He just spent 2 days in NY cleaning out basements for Sandy damaged homes, including two bus trips back and forth. He said he was sore afterwards. He's never said that before. ) And he is just starting to slow down, and he just called and said he's tempted to just pay the heating company to repair it.

I figure they'll charge 300 for the 175 dollar unit and 100 or more to put it in, so 400 or even 500, what might be fixable in less than an hour just by cleaing the probe. If it is the probe and IF I CAN GET THE PROBE OUT, I can do all this myself. If it's the control unit, that will be a 15 minute job. And I need to do more volunteer work.

[Smitty Two]

I don't think you need a milli-ohmmeter. Anything less than 5 ohms is probably interpreted as a short.

I'd not suspect a non-moving part before peeking inside that control box. If there's a mechanical relay in there, he probably just has dirty/corroded contacts.

[hrhofmann]

My guess is that it is in the sensor circuitry. If the probe was crudded up due to water deposits, it would be more likely to show there was water present when there was no water, not to show there is no water when there is water. I would be inclined to just order a new system for the $175.00, assuming that it is mechanically compatible. I would also have the new unit in hand before I took the old unit out, so that if something on the old unit fails while removing it I have something to put in to fill the hole. You certainly could bypass the old unit to make sure that that is what is actually shutting the boiler down.

[Ed Pawlowski]

Lack of maintenance may be the problem. Not the cut off as it seems to be doing the job, the boiler itself.

Has it ever been cleaned on the water side? Has the sediment been blown out on a regular basis?

You may be getting surging when the boiler is firing and that would cause trips. Is there a sight glass? If so, what has he seen? If you don't know what surging is, you probably don't know how to correct it and need to take to a pro.

Proper maintenance is critical on steam boilers. Sounds like the owner is a cheap SOB and will let it blow up before he spends money to take care of it.

[micky]

A lot of things to think about. Unless he has someone fix it, I'll probaboly be able to tell you in a few days what t he answers are to all of your questions, including Ed's.

Thanks all.

[Ed Pawlowski]

Thinking about this a little more, since it is a commercial boiler there may be even more to this. Is the boiler used only for heat? Most likely it is very low pressure. Residential steam boilers operate at less than 1 psi. Commercial, however can be 10 psi to 15 psi. After 15 psi you are in industrial high pressure territory.

Where I work we operate 3 seam boilers. One is a 10 psi heating boiler. The other two are 110 psi process boilers. Sure, they are bigger and higher pressure, but similar rules apply because of the potential danger. Any time a boiler is operated, a licensed operator must be present. I have six of us to cover all shifts, vacations etc. By law, we must check the boiler and mark a log at least every 2 hours.

I bring this up to drive home one point. Proper maintenance is critical. Steam boilers, even low pressure can become a danger if the low water cut off does not work. Don't do anything stupid, don't by-pass it. Don't try to save 50 bucks if you need help.

[micky]

I think it makes hot water too, for sinks and maybe a dishwasher.. There are no showers or bathtubs and afaik no clothes washing machines.

I think this is nowhere near that big. The building is 3 stories tall and based on my observation and estimation between 60 and 80 feet wide and 100 to120 feet deep. It's 75 or 85 years old, but the boiler is not that old, maybe 30 years.

Okay, I definitely won't. If I have mentioned bypassing the probe, that was only for a minute while the reset button was pressed, which would make the boiler start, but then right away I'd remove the bypass and if the probe was bad, the boiler would stop again. Then he would either get a new probe or call a heating company.

If pressing reset for a minute or a little more didn't make it start at all, there would be no reason to blame the probe, so we'd replace the control unit with an identical one. If that didnt' fix it, we'd replace the probe too, which comes with the unit, and if that didn't work, we'd call the heating company.

The water in not below the law water limit he tells me, and I will check for myself too. He said he'd let me know and we'd both go.

[micky]

And thanks for your concern.

[Ed Pawlowski]

You can bypass it for a minute or two. Nothing is going to happen that fast. The problem is when you walk away and the water goes low and the cut-off does not work that you have a problem.

When this cuts out, it is right away when you reset it? Or does it run for some time and you find it hours later that it tripped for an unknown reason?

If you can see the water is at proper level and it will not function, it is probably a bad probe or main unit If it is happening after the boiler runs for a while, it may well be the water inside is rocking and rolling and causing a void as the waster drops for a few seconds. You'd have to sit and watch what is happening to see that, usually under high fire and getting near maximum pressure.

If the water is surging, you want to drain down a lot of the water and replace it with fresh water. There can be a lot of dissolved solids in the water over time. You usually use a meter to determine what it is.

[micky]

I was wrong. The boiler is only for heat, not hot water. Also there is a separate device there to add water automatically when the level gets low.

Well, I'm embarrassed to say that it's not the low water cutoff at all**, but I'm proud to say I figured that out bwhen he wasn't there with voltmeter measurements. If anyone cares, I'll say what they were.

Now it appears that the problem is that the pilot light had gone out. We couldn't relight it. A chart on the boiler said this model (Peerless 244.6.n.n) said that it hjad one pilot, 10 burners and the pilot was automatic or electric (I forget which)

Pilot lighting instructions were attached firmly to the boiler, and they are pretty much the same as below**. We followed the instructions and when we pushed the red "button", my friend thought we should hear sparking and the noise of gas coming out of the pilot. (We had turned off the main gas supply and the pilot c*ck, waited, then turned on the pilot c*ck again.)

I held the red button down for about 40 seconds and nothing happened. No flame, no sparking noise or gas noise.

Should there be noises???

Should I have held the button longer????

Or perhaps the pilot switch has broken???

**This is the pilot switch, a Johnson Baso Pilot Switch L62GB-3

And this should be the manual for it:

's what Firfefox Downloads says the link was but it won't download it again so this is the google search I used: at least for me, it was the first hit, which said. "[PDF] L62GB BASO® Safety Shutoff Device File Format: PDF/Adobe Acrobat - Quick View Aug 18, 2008 ? 3. Remove the L62GB cover by loosening the screw on the front of the device. IMPORTANT: ... unit may distort and cause the safety switch to fail. 4. ... Pilot Gas. Inlet. Basotrol. Valve. Figure 1: Typical L62GB Installation ..."

FWIW, hHere's one for sale, new ,

**My friend thought it was that because he said the red light used to be on all the time, but I convinced him that couldn't be, and then he started to doubt his memory. Maybe it was just on when there was no heat and off after he pushed the reset button, he said.

Also there was a glass water tube and the water level was higher than the cutoff level.

[micky]

Or are we supposed TO USE A MATCH???

**This is the pilot switch, a Johnson Baso Pilot Switch L62GB-3

And this should be the manual for it:

I searched on baso pilot switch L62gb-3 .

Looking at this pdf file, it has on page 3 Setup Instructions that pretty much match what was on the boiler itself. I don't understand Step 4.

"Checkout Make sure all components are functioning properly by performing the following test:

1. Test all joints and connections for leaks with a soap solution.
2. Set the thermostat to the lowest setting.
3. Close the main manual shutoff valve (A valve) and the pilot valve (B valve [see Figure 1]) and wait at least 5 minutes for unburned gas to escape from the appliance.
4. Reopen the B pilot valve, push down the red lever and light the pilot burner. Continue to hold down the red lever for approximately 30 seconds.

====> I don't understand step 4. "Push down the red lever and light the pilot burner" Does that mean with a match???? I thought I read that it lit electrically, but I don't see how. There is 1) a small gas pipe coming into the pilot switch and 2) another small pipe going out, to where the pilot flame will be.

There are 3) two wires which are connected inside to a switch that IIUC opens when the thermocouple cools off (when the pilot light is off) so that the Electrical; Valve** in the pretty big gas pipe going to the burners closes, for safety. (and maybe also a valve in the switich turns off the gas to the pilot light for savety???)

And there is a thermocouple lead, that goes to where the pilot flame is, and senses wheher the flame is lit, based on how hot it is.

But where is the "sparker" that is needed to light the pilot flame???? How can the sparker work when the AC electric power has been turned off?

Or are we supposed to have or make some 12 inch extension to hold a match in there??

**See Figure 1,, Page 2.

1. Open the A valve. The main burner ignites from the pilot burner when the thermostat calls for heat.
2. Disconnect the thermocouple from the L62GB. The main valve should close immediately. If it does not close, check for wiring errors. Reconnect the thermocouple to the L62GB when it is operating correctly.

-- end quote --

[hrhofmann]

Haven't you ever lit a gas water heater. You push the button and light the pilot with a match on the end of a stick, and continue to hold the button down for 10 - 40 seconds while the heat from the pilot heats up the thermocouple enuf to open the mail gas valve.

[micky]

Not for more than 20 years. And that was only once at an ex-gf's house.

We were confused because it said it was lit electrically or automatically, I forget which. My friend doesn't remember ever lighting it in the last 10 or more years that he's been in charge of it. I would have expected to see a stick there too, but no such luck.

Thanks a lot.

[micky]

Well, everyone, not only wasn't it the low water cutoff, it wasn't the pilot switch either! After sending my friend what you all wrote here, and the instructions for the pilot switch, he called me this morning very apologetic for wasting my time and criticizing himself.

And it turned out they even had fireplace matches upstairs, to light the boiler with I'm sure. And all he had to do was light the pilot.

On the phone, the local boiler repair or steamfitting company said maybe the themocouple is failing and that's why the pilot went out in the first place. ??

He'd probably never lit the pilot before, or if he had, he forgot how. Nonetheless, I hope i'm in as good shape as he is 10 years from now.

He says he owes me big, but I enjoy his company and I learned quite a bit about boilers, so I'm happy. But I still owe you guys. If any of you have a brownie modem, I'll send you brownies. Or if you have a liquor modem, I'll send you a drink.