Honeywell L408J 1009 Vaporstat Failures

@Gordo I just installed the same vaporstat about a week ago and it was working fine. I was in my shop with my back to the boiler when the vaporstat made the same exact pop! Never heard it before today. Seems to still be working

Have you opened the top/bottom plates to that diaphragm on either of those units yet? I don't know how the Vaporstat is designed but on the Honeywell Pressuretrols, there is a free floating pellet sandwiched inside that bottom plate and it actually pushes against the micro switch to trip it. It almost sounds like that pellet is either displaced or missing allowing the metal diaphragm to just pop up more than it would with the pellet in there to push to the stop on the micro switch. Just a thought.

MilanD said:

Hm... How old were the units? I got 2 of them about 1 and 2 years old, low-hi-lo is about year old, and op limit one is 2 years. All work done with year old unit. No issues so far. Click is very gentle for low stage. Not this pop that almost sounds like the diaphragm turned rigid. Any chance it got cooked with steam?

I'm not 100% sure but I think the Honeywell Vaporstats, like the Pressuretrols have a metal diaphragm. No rubber to cook.

@MilanD , Yea, I have the same Vaporstat also, about three years old. I'm wondering too???

MilanD said:

> @Fred said:

> @MilanD , Yea, I have the same Vaporstat also, about three years old. I'm wondering too???



@Fred



Seems like a bad batch... With all the talk here of regular Honeywell ptrols being out of calibration out of the box, would surprise me if new qc manager just shrugged and shipped it anyway... Imagine the cost of having to redo a whole run. This way, if it lasts a year, you're sol...

What we don't know is if these were all from the same run or production facility. This may be another case of engineered failure at some average life Or as some manufacturers call it " Life cycle management"

All this makes me glad I snagged a NOS mercury switch vaporstat 8 years ago. It was spot on calibration wise as long as it's level when hot.

It's really a shame they nixed anything with mercury in it.

Bob

I have a similar issue. I replaced a Honeywell pressuretrol with a Honeywell L408J1009 vaporstat because my burnham independence kept running past the set limits only to stop when the high pressure manual reset pressuretrol would trigger. Boiler was serviced and skimmed in november and was running with no issues till this deep freeze. Im guessing the thermostat was satisfied before the reset kicked in when it was more mild.

the vaporstat makes that loud click at about 4psi and clicks again at .5 psi. I have it set for 12oz main and 6oz diff. The vaporstat is brand new and still does the same thing my pressuretrol was doing. I cleaned the leads to the pigtails, put new brass pigtails on both, added a 0-15psi gauge with the vaporstat. lwco trips it, themostat calls for heat correctly, manual pressuretrol trips it. I cannot figure out why it runs past the new main vaporstat and the previous pressuretrol. The only time it stops is when thermostat is satisfied (rarely with these cold temps), or the high pressure pressuretrol trips. system is insulated, tight, heats quickly at 1-2 psi, nothing that indicates an issue.

Please help, with a new baby in the house im tired of manually running the unit for 35mins every other hour.

@JMal I’ve got the same boiler also. Not sure what area you are in, but I’d consider changing out the vaporstat again. You probably had to order yours online, like I did. If you are in the north east, supplyhouse.com is a great company and they ship out of Long Island. I think you can even drive there to pick up the part. Baring that, you might want to consider picking up a regular Pressuretrol from a local house for the time being. I feel your pain man, I’ve got a 9, 5 and 1 year old in my house.

Can you dial down the “high Pressuretrol”? You can get them down to 1.5 or so at the bottom of the main. Mine failed last week and pressure was building to 3.5 before cutting out and it was set to 1.5, that’s why I picked up the vaporstat instead.

@Gordo @adambnyc I just got it on wednesday from supplyhouse. I tested the microswitch. seems to not function. I ran the boiler till the high pressuretrol tripped. shut down the power. high pressuretrol read open resistance, then "0" when reset. The main pressuretrol read "0" several psi over the settings even with the click engaged when it got to 4psi. I waited to 0 psi, it unclicked at .5psi still read "0" . That microswitch never broke if i understand this correctly.

@adambnyc im in the bronx, supplyhouse is where i got it, came in fast as you mentioned due to proximity. I left the high pressuretrol at the original setting so i can actually get some run time in to maintain some sort of temp in the lesser used portions of the house. I dont want it to trip too much sooner since its a manual reset and that requires me going down and clicking it. at least i know that one works reliably...

My 0-30psi gauge and my new winters 0-15psi gauges which come from outlets very near each other read about 2.5 psi different. The winters is Tee'd off the main vaporstat pigtail and its the one that 2.5 psi lower. The main gauge and the high pressuretrol seem to be about the same sensitivity which is interesting that the 0-30 seems more accurate than the brand new 0-15... im so frustrated everything is annoying me now i guess.

@nicholas bonham-carter thanks, i was scrolling supplyhouse to no avail. when i get a vaporstat that works i will swap it out for 0-15oz or 0-20 oz gauge and move the 0-15 psi to the high pressuretrol side since thats what my safety valve is

@adambnyc i put my old pressuretrol back and packed up the vaporstat to exchange. My vaporstat made that same loud pop you were getting. i found it oddly loud too. ill try and upload the video i took before i took it off.

Same exact pop that I was getting. I got my vaporstat about a week ago or so. Is that around the same time you got yours? Bad batch maybe?

@Gordo You nailed it, I fat fingered it - the correct acronym is MTBF

The problem is you can predetermine the number by selecting the way you calculate ir. Unless you know how the number was calculated it's meaningless.

I feel pretty disappointed about these failures. I had a boiler that was cycling on the secondary high limit (not manual reset). 5 lb pressure, spitting air vents, water logged radiators. The vaporstat had totally failed.
I tore mine apart. Shown is the diaphragm. It is stamped metal and works somewhat like a bellows. It is over sized I guess to provide enough energy to move the levers inside with such low pressure.
When I removed this one and blew on the bottom port I got a mouth full of water. Hum...not sure if water should have worked its way inside the diaphragm or not and if that would factor into the failure.
When you look inside, it is a rather crude device. When the diff is set low, it does not even come into play. There is almost like a nature differential with just the amount of travel necessary to move the micro switch.
When I push on the bottom to simulate the movement of the diaphragm, the levers and linkage moves and starts to push on the mirco switch. When the linkage stops, or bottoms out, sometimes the switch has still not clicked. I had to push harder than I would have through necessary to get the switch to trip.
Also, if you look at the back there is a chrome button that can be removed and a screw adjusted to make the switch more or less sensitive.
My next step is to get a low pressure gauge and test this one and play with the adjustments.
I would also like to look into some other brand or a better device that might not be so crude and not too much more dollars.