Honeywell L408J 1009 Vaporstat Failures

Gordo

Over a relatively short period of time, we'd had three L408J (non-mercury) vaporstats fail. The failures all involve vaporstats that bench tested ok, and appeared to work on their respective systems for awhile, but suddenly stopped controlling the pressure at "vapor" ranges, and allow extreme pressures to build up. When these vaporstats are removed and bench tested again, the diaphragms all make a fairly loud "pop" sound when pressurized.

Anybody else have this issue?

Gordo

Here is a quick video of the "pop" test of the most recently failed vaporstat:

https://www.youtube.com/watch?v=Td1fQOCxIH4

Jamie Hall

Got to admit my first reaction is what is the common factor that is plugging the port to the pressure sensing chamber?

adambnyc

@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

Gordo

@adambnyc : Glad to hear its still working. Do you have a low pressure gauge on your system?

As you can see from the video above, the unit is set to 6 oz/in2, but "pops" considerably above that.

But here is the kicker, the micro-switch doesn't shut off even at 15oz/in2!

Fred

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.

adambnyc

I have 2 vaporstats, one controlling the cut out and one controlling the dual stage burner. I downfire at .5, but right before that, I hear that same pop, then one second later, the normal sounding pop then the boiler properly downfires. I’ll make a video and share also

Gordo

@Fred: I have not had this particular one apart (yet). I took apart the second of the three (so far) failures and just could not get it to work. The diaphragm of that one was just too badly puckered.
I may have better luck on this one.

MilanD

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?

Fred

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

> @Fred 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.

Whatever the material, qc must have lacked with the run of controllers Gordo has... Since he had 3 fail I'm just wondering what the commonality would be.

Fred

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

MilanD

> @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...

Fred

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"

Gordo

I'm not going to blame QC for these failures. They were bench tested by us before they were installed and worked at that time.

I think the failures may be due to hammering inflicted on it by dirty boiler water AND an underlying design issue. Why do I say that?

We've used many old-style mercury vaporstats in the past on new installs and we've never had failures like this.

The commonality in the failures we've experienced thus far correlates with the non-mercury design and new install with dirty water.

If anyone installs these on a boiler after it has been cleaned, they should work fine for years.

But it may be prudent to install a pressure snubber also. You never know if a customer will send a radiator out for re-finishing in the future and it comes back with the insides soaked with lye.

It is amazing what THAT will do to the boiler's water!

In order for a safety control to get the UL listing, I've been told, the controls have to be cycled 100,000 times without failures.
They just didn't take into account crazy water in boilers.

https://www.youtube.com/watch?v=3dBTUp7SAMo

Notice in this video above, the nice quiet "clicks". This one pictured is still on the job, working well.

BobC

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

MilanD

Well, glad you figured out the commonality, @Gordo.

JMal

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.

Gordo

@JMal : I am heartily sorry that you are having issues with your new vaporstat.

Thank you for letting all of us know that we are not the only ones having issues with this model.

It helps us all, because when we confront the Honeywell reps with this issue, we can throw in their faces the contemptible lie: "This is the first we ever heard about it. You are the only one who has this problem."

I hope your unit is under warranty so you can get it replaced soon. I would advise not trying to repair it yourself.

I, myself, would try to fix mine because the one pictured above is date coded 2014 (out of warranty - nothing to loose) and I carry beaucoup amounts of liability insurance.

adambnyc

@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.

nicholas bonham-carter

In order for a safety control to get the UL listing, I've been told, the controls have to be cycled 100,000 times without failures.

How long will it take to cycle anything 100.000 times?
I am sure the manufacturer will say, “we think our device will cycle 100,000 times”, and UL will say, “thank you, that will be $100,000. 00 for your certification”!
Thank god I have the old mercury model!—NBC

JMal

@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

A 0-3 psi gauge graduated in ounces is what is needed here.
Valworx.com 0-3 psi is best until you have the pressure down low, then a 0-16 ounce gauge is better.—NBC

JMal

@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

JMal

also side question, teflon or pipe dope on threads?

Gordo

@nicholas bonham-carter : It's what I was told about the UL listing process. They only have to pass it once, and as long as the manufacturing procedures are unchanged (subject to periodic announced friendly inspections) that's it.

I was told the design goal of a fail safe safety control is 100,000 cycles or ten years.

I am told that a certain number of a particular control that desires to obtain the Listing are put into a room and hooked up to manifolds or whatever and to counters and just cycled and cycled and cycled and cycled until each of the controls under test has cycled 100,000 times without fail.

Do they cheat? I hope not. Quis custodiet ipsos custodes.

nicholas bonham-carter

How long would 100,000 cycles take to perform????????—NBC

Gordo

Well, there are 24 hrs in a day, 60 min. in an hour and 60 seconds in a min., therefore there are 86,400 seconds in a day.
Lets say it takes 20 seconds to do a cycle, that's 4320 cycles in a day. That makes a bit over 23 days.
If it takes a minute to do one cycle, that's 69 days to do 100,000 cycles.

BobC

I used to do a lot of UL certification and I really don't have a lot of faith in them especially since they allowed companies to self certify. UL certification is about as useful as calculated MBTBF.

Bob

Gordo

@JMal : Pipe dope should be just fine.

adambnyc

Of course... finally get the camera out, wait for the pressure to build and nothin... back to normal pop.

JMal

@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.

JMal

https://www.youtube.com/watch?v=39bXqNWJ7WI

adambnyc

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?

JMal

@adambnyc. I got mine Jan 3rd. mailing it back today for an exchange. i hope its better... did yours pop twice when coming down from pressure? Mine had a loud pop like this one and then a lighter tinnier ping at like .25 psi.

now that it warmed up and manually ran it to get to set temp, i put my pressuretrol back now the heat is running again. It doesnt have to cycle long enough to get to high pressure to catch up anymore so its back to thermostat cycling. Ill still put the vaporstat on when i get the replacement because i have always wanted to swap it and already bit the bullet on the cost of it.

Gordo

@BobC : Please, what does MBTBF stand for? Something about mean time between failures?

adambnyc

@JMal exactly the same sound as you describe, and I ordered mine the day before you did. Same batch I’m sure. Quality control issue. At least you got the Pressuretrol back on so you don’t have to babysit anymore.

BobC

@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.

Fred

BobC said:

@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.

In most cases, at least in the electronics industry, when I worked for a major manufacturer, MTBF was calculated based on actual component failure rates, during the product warranty period, when parts were exchanged at no cost. Not at all a good representation of product life beyond the initial year. As warranties drop to, in many cases 30 days, MTBF significantly improved because far fewer components fail in 30 days (although they claim electronics will most likely fail within the initial 30 days).

Dave Stroman

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.

Fred

@Dave Stroman , see : https://forum.heatinghelp.com/discussion/156690/a-diy-vaporstat-alternative