MM 67 LWCO

STEAM DOCTOR

Are there boilers that still come with the 67 LWCO or do all of them come with the probe type? I am asking because I took a delivery today of a new boiler for installation and much to my shock it had a 67 LWCO and no provision for a probe/electronic LWCO. I called the manufacture and they confirmed that there is no provision for the probe,This was my first/last experience with particular model.

Joseph_4

happened to me today to

I also got a boiler today with mm 67lwco. I called manufacturer and there is no tapping for the probe type. was surprise for me too

Joseph

gerry gill

oh yah..

lots of boilers still use them..they actually are very good as long as they are serviced.

STEAM DOCTOR

Why

Is there a good reason to use something that needs to be serviced once a week  when you can use something that needs to be serviced once a year?

Steamhead

It depends

on whether someone has the responsibility of servicing it. In commercial situations  someone generally has that in their job description. Not in residential.



Which boiler are you talking about that doesn't come with a probe?

Rod

M&M 67

Look at it from the positive side. Having to blow down the Low Water Cut

Off once a week forces you do do a weekly boiler inspection which you

should be doing anyway. A weekly inspection allows you to catch problems

before they become serious and possibly dangerous. Some people have

both an M&M 67 AND a probe installed on their boilers. (Sort of a belt and suspenders)

STEAM DOCTOR

Slant Fin gxha-200 with tankless coil

This a residential boiler. If all customers are like mine then you have to assume that they will not do any maintenance no matter how much you educate them. I have put in slant fin galaxy before and I love the speed skimmer and the 2.5" steam tapping. HOWEVER there are several serious issues that I have with the SF steamers. 1) The tankless modal has no skim tapping at all.The manual says to put a T in the pressure valve tapping and skim from there. NO WAY! 2)The tankless model has the MM 67 LWCO not a probe/electronic LWCO. 3) All of the SF steamers have a return line tapping only on the right side of the boiler. This obviously wont work very well if the header is slopped toward the left side of the boiler. There is a tapping on the front of the boiler near the left corner. It is behind the front panal and is hard to work with. In order to use that tapping you need a 1.5" street elbow. That tapping is also not listed in the I&O manual. 4)There is no separate tapping for a boiler drain. 5)The I&O manual calls for a 2.5" equalizer down to the Hartford loop T. OVERKILL!!! 6) The controls are very close to the return tapping. It makes it a big pain to work with. With the tankless modal it's more of an issue because the MM 67 comes very close to the tankless tappings.

oldman

mm lowwater cutoff

This brings back a problem one of the large hospitals here had with one 1000 hp boiler and the situation has not been forgotten. The boiler being over 50 horse power requires the Department of Labour to check it once a year for any problems the boiler might have developed over the last year. The inspector looked into the back of the boiler where the main chimney was located and low and behold the  mud tank on the very bottom of the boiler had no way to do a blow down. This boiler was site built by contract and I am sure at that time, the blow down was not required. Now, to the low water cutoff --  after the welder was finished welding in thread o let the inspector wanted a pressure test of the new weld and the entire boiler. The engineer took the old beast up to 110 psi and left it over night - the boiler normally ran at  60 psi for sterilizers anyway. The winter came as usual and the  second boiler was put on line not the repaired one. The boiler ran great, lots of steam and happy people -- until the week ended and as was routine, the boiler with the pressure test was put on line. It ran for about eight hours and then the low water signal bell went off. This is serious with this kind of horsepower; the boiler does not cool off in an hour. The engineer checked the water level it was fine? So he reset the boiler and sure enough off it went on low water again. This went on for weeks - the electricians could find no fault - the plumbers gave up - and the engineers did what they did the best; watched television. Finally, someone phoned, at that time, the best boiler service people in Winnipeg Combustion Services. The serviceman tested everything -- nothing wrong???? So in desperation he contacted the old man of boilers; the owner of the shop. He came out looked it over and did what every serviceman has to learn -- talked to the customer. He found out the pressure test had been done and immediately knew what was wrong. The boiler had a four probe system to sense low water and of course all the probes had to be submerged for the system to be satisfied and let the boiler run. What had happened was, the pressure test had caused a leak at one of the upper most probes, and enough water was escaping to just leave the probe slightly exposed -- off it went on low water, The loss of water was not enough  to show up in the site glass so the engineer correctly could not find a low water condition. The probes were changed and no more low water. Moral of the story; blank the probe area off when you do a pressure test it proved to be rather expensive to repair.

All the best and hug your kids they are the future we are the past

Jack Ennis Martin

STEAM DOCTOR

Gerry

Have you had boilers with no option for the probe LWCO?

STEAM DOCTOR

Gerry

Have you had boilers with no option for the probe LWCO?

ChrisJ

I'm a bit confused also

My boiler has a location for a probe, but has a #67 installed.



This is all well and good but I don't understand why.  A #67 is quite a bit more expensive than a probe type and yet requires maintenance which means more makeup water.  Is there a benefit?  Is the #67 considered safer when used properly?

Greg Maxwell

LWCO

As a wholesaler, I cant see why they would opt for a 67 unless its prevelent in their area because its what the steam guys know and trust. I remember when we first were offered the probe type LWCO's on our boilers, and the tech's were very skeptical. As I'm sure you know, its hard to change from something you've trusted for years.

STEAM DOCTOR

probe

I think they didn't want to tap the boiler an extra time. On the modal without the coil there is a tapping for the probe and for skimming. On the modal with the coil there are two tappings for the coil and no tapping for the probe or skimming

ChrisJ

No Skimming!?

Wouldn't this make a boiler completely useless?  You would not be able to remove the oil and garbage from the surface of the water after installation.



bn,  I was speaking in reference to my Burnham boiler.  It has a tapping for the probe but it was not used, instead the installer used a #67.

I have to assume what Greg suggested is true in my case.  The installer went with what he preferred.  Burnham shows both the #67 and probe in the manual.

My hopes are in the future to go to a Hydrolevel probe and VXT.  I just bought a replacement ball valve for my #67 though because money is hard to come by right now.

BRIANJ

LWCO VS PROBE

I removed the probe from my Peerless 63-06 and installed an MM67. Why? Because the probe shut down the boiler every 10 minutes to check for low water and this would interrupt the steam cycle. A full minute later the boiler would come back on only to be interrupted again in 10 minutes.

I have an old Broomell system and checking the boiler and flushing out the rust from a 100 year old system is easy and I believe not beyond the intelligence of the average home owner.  Then again if the home owner doesn't know how to make a peanut butter and jelly sandwich then they should probably go with the probe and not damage the boiler. Just my 2 cents.

STEAM DOCTOR

T on top

The I&O manual says to put a T where the pressure relief valve connects to the top of boiler and to skim from there

STEAM DOCTOR

T on top

The I&O manual says to put a T where the pressure relief valve connects to the top of boiler and to skim from there