Old Watts LWCO sill available

GW · January 26

is there any likelihood I could rebuild this low water cut off?

Or, chuck it and put on a 67

it’s a millivolt so that adds to the joy

The lady somehow overfilled the boiler, I took 20 gallons out of it, brought it down to the very bottom of the boiler still wouldn’t shut off.

mattmia2 · January 26

it is millivolt but it is all wired in romex?

you could probably take it apart and clean, the float is probably just hung up on muck it although replacing it with a MM would be a great idea for safety reasons.

Steamhead · January 26

That Watts hasn't been made in a long time. Get a 67-G, not a regular 67- the G is millivolt rated.

Intplm. · January 26

Disconnect the copper tubing off of the top and use a hose from a sillcock or any source of street pressure and run water through the top. That should flush the thing clean and get it working.

tim smith · January 26

Old Roberts Gordon burner, worked on many of those over the years. Agree on the Macdonal Miller 67-G with quick connects. Supply house is out of stock but cheaper than others. Not avail till around february 11th. https://www.supplyhouse.com/Mcdonnell-Miller-149600-67-G-67-Float-Type-Low-Water-Cut-off-for-millivolt-service-Steam?srsltid=AfmBOoq3m8nT5e2fZVDmT9PO_xSAmXMtLJkk00wNVatR0kXE3YtvlMue

Looks like maybe State supply has one or more in stock, you would need to verify.

https://www.statesupply.com/mh1066?srsltid=AfmBOopIPUDeVFFjYlVIFAPvFENvPurDzQn9EmOvJBXzHZkQufckwvmP

mattmia2 · January 26

sometimes stuff that supplyhouse.com shows as out of stock or with long lead times miraculously shows up when you order it

GW · January 27

@tim smith a couple years ago I posted the same boiler on the wall, I believe. We are chewing through powerpiles, every couple years we have to replace. Somebody mentioned, might’ve been you, we are overheating the powerpile. And there was some gadget that was there at one point, no longer there, that kept the from it from overheating.

Does that make sense? Can you think of any way that we could make the power pile last longer?

tia

mattmia2 · January 27

some here have sad that the baso thermopiles are better quality than the wr or residio resideo? residewell?

109A_5 · January 27

I have cleaned my M&M 67 twice in 50 years. I bet that LWCO could be cleaned, you may have to make some custom gaskets. I stopped using the paper gaskets, although they are available for the M&M 67. I made reusable gaskets out of 1/32" silicone rubber sheet material. Makes the job easier.

EBEBRATT-Ed · January 27

@GW the Watts is still listed on their web site. Don't know if parts are available. looks like a Smith model 24. They lasted forever.

How many wires into the LWCO. That looks like K & T wiring or maybe old Romex.

Vapor system.

mattmia2 · January 27

either early romex or individual wires in loom.

EBEBRATT-Ed · January 27

@mattmia2

Looks like loom to me as well. That's why I asked about # of wires in LWCO. Loom it's two Romex is 4. Looks like conduit going up overhead from burner so probably a JB up overhead

109A_5 · January 27

If you look at the cable placement, it looks like there is only one cable to the pressure switch, so I would say two wires per cable assembly (or loom).

One wire per cable assembly would not work unless they used the piping for a return at the pressure switch.

GW · January 27

https://forum.heatinghelp.com/discussion/comment/1884378#Comment_1884378

pretty sure its Resideo in there now. It's definitely overheating. The burner drops out, and I then measure the MV (where the pp connects to gas valve, and the stat-safety is off the vale/disconnected). The numbers slowly climb on the off cycle. When the numbers climb enough, the main burner comes back on (when I reconnect the stat-safetys). And the process repeats.

GW · January 27

Nice, I guess making gaskets can't be super difficult, I will google that 1/32" silicone rubber sheet material

mattmia2 · January 27

you can probably just use permatex too unless the gasket is shimming some critical clearance but i doubt it is in something like that.

GW · January 27

I ordered the 1/32"

I forgot to get some exacto knifes, i'll hit up amazon again

Not sure why I am trying to keep this on the cheap, the lady pays full price and she also kicks cash tips. Yesterday she asks" do you have kids". I say I have two adult kids and two grandchildren. She pops a $50 in my hand and says this is for your grand kids 😊

109A_5 · January 27

I used something like this. It was years ago when I bought it.

Red Silicone Rubber Sheet 60A 1/32 x 9 x 12 Inch Made in USA Gasket Material

https://www.ebay.com/itm/234098580147

When I take it apart I just rinse it off with warm water, and reuse it, no more gasket scraping. So far I like it.

tim smith · January 29

Gary, it may have been that on some of those burners there was a 2 piece refractory diffuser plate that sat on top of vertical burner blast tube. Peopley would run them with out it but not ideal, quite inefficient too.

Alternately it could be too strong of pilot and burning out generator. Just couple possibilities.

The one that had to plates on top had a cast iron blast tube that went into combustion chamber from burner housing and then had an elbow on end that turned up. The refractory would sit on a cast iron tripod like piece on top of that turned up elbow.

GW · January 30

Tim I should have taken more pics. The blast tube sends fire and hits the cast iron tripod. The power pile does not seem to get too much pilot. I’m getting like 510 mv when the powerpile is connected to the gas valve (stat and safety’s disconnected). My issue is the mv plummets after a heat cycle. So I’m reluctant to test mv droppage across the stat and safeties because the darn burner won’t come back on for a while ( could be minutes, could be hours).

Do you have experience with converting to 24v? Any pitfalls that can bite me?

mattmia2 · January 30

are you getting that from a new thermopile?

read starting around page 6 of this:

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Honeywell%20-%20Q313U3000%20-%20User%20Guide.pdf

you may need to shield the base of the thermopile from the heat of the burner because it generates voltage based on temp differential

GW · January 30

yes, new. It’s a head scratcher. I think the gas valve may be getting tired.

most concerning is the powerpile is in the heat of the “blast”, I’m unsure how the original set up was configured, how the pp didn’t get hammered with heat

the boiler seems like it will last another 100 years, but keeping the old beast running and running safely is getting to be a challenge.

I can throw time and parts at keeping the pp system or maybe change to 24v. But the powerpile or thermocouple will be hammered with heat regardless

Switching burners is an option perhaps. I would have to get a metal guy to make a setup to hold the new conversion burner on the “mid section”, all semi sketchy and time consuming

Or I tell the nice old lady “this is too much effort- if you want the question marks to vanish we need to slide a new boiler in there “. In which case I would then need to deal with the vapor system aspects.

pros and cons

mattmia2 · January 30

look at the last page of that sheet for the thermopile where it talks about building a shield to draw excess air over the base of the thermopile. the voltage is generated as a result of the temp differential between the base and tip. if the burner is heating the base the output will fall.

109A_5 · January 30

The newer electronics version of a hot water heater tank gas valve that has the power pile has what it looks to be a heat shield, like @mattmia2 mentioned. If the heat shield is missing in this unit that may be the problem. I'll try to find a picture later today.

mattmia2 · January 30

there is a diagram in the honeywell tech sheet i linked to

GW · January 30

yes I looked at that this morning. Are you familiar with upshot burner. The power pile is completely immersed in fire. A water heater is much different than what I’m describing.

mattmia2 · January 30

so then how did it ever work? that was a common burner 70 years ago.

109A_5 · January 31

https://forum.heatinghelp.com/discussion/comment/1885379#Comment_1885379

I get that, but it does not change the need for the temperature differential that @mattmia2 mentioned for a power pile to work correctly.

It may have never been set up correctly and thus always been marginal in operation.

The water heater is just an example of the need for the heat shield for proper, reliable operation.

How you resolve the issue is up to you.

mattmia2 · January 31

i think baso has a high output thermopile, that would compensate somewhat for not being able to keep the base as cool as it should be.

mattmia2 · January 31

it might be missing a part for the burner, this is a @Tim McElwain level question. might still be able to call him if he doesn't see this.

109A_5 · January 31

Another example. See how only the upper half of the power pile gets heated by the flame, primarily the pilot flame. Sounds like you are fighting a situation where the power pile positioning was never set up correctly.

GW · January 31

yes, those illustrations , but that’s not what I’m describing at all. If you’ve ever seen this burner in real life, you would see what I’m trying to explain.

I’m in a little bit of a corner, 1/2 of me is trying to keep this old boiler going. The other half of me is trying to keep the 8 lady from freezing.

yes, somebody out there has the answer. It’s just one of those things I guess.

EBEBRATT-Ed · January 31

Guess they don't make upshot burners anymore. The only one I saw was an Adams and based on one of their oil fired furnaces I installed I would buy NOTHING from them.

In the old days we would take the fire door off and fill the old ash pit in and fire a burner through the door. Problem with that is asbestos removing the old burner etc, Carlin EZ gas.

mattmia2 · January 31

it's like one of those weed burner torches pointed up at a disc of either refractory or steel/iron. they had some way of keeping the cool end of the thermopile cool, @Tim McElwain will know exactly how they did it, a few other old timers here might know too. a part might be missing or be a pile of rust in the bottom of the boiler or it might not have been reassembled in the right position 30 years ago. you could replace the valve with a modern combination standing pilot total shutoff 24v valve if you know enough to get the combustion set up right afterward. you'd have to replace the t-stat with a 24v t-stat too, not sure if the other controls are ok with 24vac on their millivolt contacts but the anticipator in the t-stat won't work righ on 24vac.

109A_5 · January 31

I've seen up shot burners, but can't find a good internet image of one that the power pile would be completely engulfed in the flame of the main burner. That leads me to believe your pilot / power pile mounting strategy is not correct and it needs to be corrected. Or a heat shield is missing.

mattmia2 · February 1

maybe it is overfired or someone changed something that change the way it is burning like with less excess air or something.

Steamhead · February 2

https://forum.heatinghelp.com/discussion/comment/1885519#Comment_1885519

Adams makes two- the HU and the SPT:

https://www.adamsmanufacturing.com/pdfs/speedflame2.pdf

109A_5 · February 2

https://forum.heatinghelp.com/discussion/comment/1885736#Comment_1885736

I saw that page, but I don't believe that the power pile would be completely engulfed in the flame of the main burner in those examples.

mattmia2 · February 2

https://forum.heatinghelp.com/discussion/comment/1885736#Comment_1885736

i was hoping you'd be one of the 50 people that still knows how that burner was intended to keep the cold end of the thermopile cold

or maybe @retiredguy

mattmia2 · February 2

https://forum.heatinghelp.com/discussion/comment/1885750#Comment_1885750

i'd imagine that any new burner is going to use a 24vac or line voltage gas valve

GW · February 3

OK I was mistaken——the Power Pile is not completely engulfed in the flame. It simple bewildered me and my memory was not accurate. I was there today with my lead guy he was there all day and I wad there 1/2 day, to change the gas valve! Yes, that's right about 11 or 12 man hours to change a valve. It was not cake.

We put in a RobertShaw valve and we tied the PowerPile to the gas valve, not the full-time gas line off of the gas supply.

OH- and the LWCO now works too. My other lead guy opened up that bas larry and cleaned out out, cut a new gasket, all good. It's super peculiar, the low water drops the flame before the water gets to the bottom (where the float actual resides). I can't wrap my head around it. But we dropped the flame out once and we beeped it twice, so it's good to go.

Tile will tell, hoping to get a good report tomorrow (she still has heat)

Old Watts LWCO sill available

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