Vaporstate backup/alternative

Knave72

I bought a Vaporstat from SupplyHouse last year a the end of the season ($240) - finally figured out that this was the source of the problem I was having (water flowing out top vents and general over pressuring).

At the beginning of this season the problem was back. The vaporstat simply wasn't cutting out at the shutoff pressure. If I *whack* it, it cuts off and if I fiddle with it enough it starts behaving for awhile but eventually stops working.

SupplyHouse gave me the Honeywell support # and I just haven't been able to get them on the phone yet... tbd on whether I can get it fixed/replaced.

BUT - I decided to create my own "backup" pressure control using a raspberry pi pico and a pressure sensor from amazon ($18)... all in I think I'm in the $50 range (honestly haven't added it up yet) but the cool thing is it has a digital display which means much better visibility into what's going on.

It works the same was the vaporstat would... at a max pressure it shuts off and then back on at a min which is programmable.

If anyone is comfortable with the raspberry pi and would like details, let me know. A picture of my display is shown as it was coming "down" after a shutoff.

It shows the average pressure (I have a 5 sample running average) and the current pressure reading up top and down below you can see that it has cut off the boiler.

With this approach, you control the display so you can make it whatever you want... count the cycles, display average on time, etc, etc.

Rough parts list:
Raspberry pi pico ~ $10
LCD Display $15 (optional but much cooler with it)
Pressure sensor $18
relay

K

KC_Jones

Water flowing out of vents isn’t a pressure problem, it’s some kind of piping problem.  Water shouldn’t be up in the pipes to come out of the vent at any pressure.  The pressure control is “fixing” it because it’s shutting off the boiler before the issue can present itself.

I’d suggest you still have other issues in the system.

I just looked at your other post and the boiler piping is definitely not up to spec.  I’d need to have the exact model of boiler to double check, but eyeballing it, that looks like the size that requires both risers in 2 1/2” pipe.  Not even sure if you have a single 2 1/2” pipe, might only be 2”, but you’d have to measure to verify.

That piping is certainly the cause of the water carryover, if you get enough no header will be able to handle it and do proper separation.

Link to the manual for that boiler, if you have a 5 section or larger it’s supposed to use both risers.

https://dunkirk.com/wp-content/uploads/2022/03/615000243-REV-A-PSB-NEAR-BOILER-PIPING.pdf

reggi

Knave72 said:

I bought a Vaporstat from SupplyHouse last year a the end of the season ($240) - finally figured out that this was the source of the problem I was having (water flowing out top vents and general over pressuring). At the beginning of this season the problem was back. The vaporstat simply wasn't cutting out at the shutoff pressure. If I *whack* it, it cuts off and if I fiddle with it enough it starts behaving for awhile but eventually stops working. SupplyHouse gave me the Honeywell support # and I just haven't been able to get them on the phone yet... tbd on whether I can get it fixed/replaced. BUT - I decided to create my own "backup" pressure control using a raspberry pi pico and a pressure sensor from amazon ($18)... all in I think I'm in the $50 range (honestly haven't added it up yet) but the cool thing is it has a digital display which means much better visibility into what's going on. It works the same was the vaporstat would... at a max pressure it shuts off and then back on at a min which is programmable. If anyone is comfortable with the raspberry pi and would like details, let me know. A picture of my display is shown as it was coming "down" after a shutoff. It shows the average pressure (I have a 5 sample running average) and the current pressure reading up top and down below you can see that it has cut off the boiler. With this approach, you control the display so you can make it whatever you want... count the cycles, display average on time, etc, etc. Rough parts list: Raspberry pi pico ~ $10 LCD Display $15 (optional but much cooler with it) Pressure sensor $18 relay <$10 Power supply - just used a +5V from an old network switch I had laying around. Case - small carboard box compliments of amazon. K

Count cycles, Average time,... without sitting in the basement? 
I'd like to see the details on this.. pretty much from scratch because I'm not familiar with the Raspberry pi ...
Thank for the offer 

Jamie Hall

Nice gadget. Pity that it's not doing anything useful to fix your problems -- including getting the vapourstat to work properly -- but the arrangement of deck chairs is more attractive, anyway.

BobC

@Knave72 I'd be interested in seeing more about your PI setup, which pressure sensor did you use?

Bob

Knave72

@KC_Jones thanks for that feedback - I would definitely like to get to the root. My biggest problem is literally no professionals in the area who can or will work on a steam boiler, so I'm left no choice but to try and figure it out myself with no prior experience.

I will follow up on the information you provided and see what options I have.

KC_Jones

If they can’t turn pipe with direction on where the pipes go, they literally shouldn’t be in business, steam boiler or not.

I may have missed it, where are you located that you can’t find anyone?

TonKa

It is my understanding that a vaporstat or pressuretrol is not an operating control but a safety limit, although it also frequently functions as a defacto operating control.

While what you have put together fits your needs, it is clearly an operating control. You may want to consider putting a manual reset high limit pressuretrol in series and set it to a bit higher value than your Raspberry Pi.

Long Beach Ed

Expanding on TonKa's observation, a homemade safety control may be frowned upon by inspection and insurance concerns. You do have a pressure relief valve (check it) which provides safety but the recommendation of a redundant mechanical control is a very good one.

Chris_L

A number of us monitor pressure electronically with various hardware/software and use it to shut off the boiler. (I use an ESP8266 and probably the kind of sensor as you.)

The main advantage of doing so is that you can control the amount of time the boiler stays off, something you can't do with a Vaporstat or Pressuretrol. This allows you to even out the calls for heat and reduce overshooting the thermostat set point.

I agree with others that if you've got water flowing out of your vents you have other problems, and that you should only use the electronic control as an additional shut-off, not as an alternative. My millivolt system has two Pressurtrols (one for full shut-off) that I've left on as backups to the pressure sensor.

As for the sensor itself, I've found it works best if it is not on a pigtail. Install it a foot or more above the top of the boiler. (I thought I saw of photo of your setup, but can't find it now.)

You might do the same for your Vaportsat to see if it works better. Taking if off the pigtail will be against code and the manufacturer's instructions, thought if mounted up high it will see only air and should be fine. Keep your old Pressuretrol on a pigtail as a backup.

ChrisJ

I see nothing wrong with a home made control as long as there are still real controls that can shut the boiler down. I.E. a Pressuretrol wired in after yours set to 1.5 or 2 PSI.

That being said,
You need to do better than a cardboard box.

And, what's the reason you can't correct the piping? Are you good with your hands? Can you buy some tools, even Harbor Freight? Many people make fun of Harbor Freight pipe wrenches, but that's exactly what I used to do most of my steam piping. I'd recommend a 14", 18", 24" and two 36" although I think I ended up with two 48".

Are they good enough for someone that uses them every day? No, but they're more than good enough for you to do what you need to, and likely anything else in the future as well.

Use off the shelf threaded nipples and if you need 1 or 2 lengths custom threaded I'm sure you can make do with a local plumbing supply or Lowes/Homer.

If you're good with your hands and mechanically inclined, you can do it.
If you're not, then I wouldn't recommend trying.

109A_5

Chris_L said:

(I thought I saw of photo of your setup, but can't find it now.)

@Chris_L, maybe you were thinking of this thread, as far as a sensor in the picture.
https://forum.heatinghelp.com/discussion/190166/short-cycle-vaporstat-problems

Knave72

What a great group this is...

@KC_Jones - I'm in Columbus Ohio. I've had 3 different local companies come out, look around for awhile and then tell me they can't help.

This is my first steam experience and I'm much better with electrons and lines of code than pipes and wrenches but I'm up for anything. When I spoke to some plumbing people about this previously they said they wouldn't even do just the plumbing side - that is should be done by HVAC people.

My device was really only ever meant as a backup...

Could someone elaborate on what the "correct" or recommended pressure control setup would be for a home system? And is it normal for these things to fail so quickly or is that a symptom of another problem?

The cardboard box is just a stop gap until I 3D print a proper case with screw holes that fit the small boards...but it was really convenient and does the job at the moment!

Knave72

"if you have a 5 section or larger it’s supposed to use both risers"

How do I know how many sections I have? I looked up the manual and the only use of the word "Section" is literally to say the same thing... less than 5 sections is a single riser, 5 or more is 2 risers.

Jamie Hall

The usual setup for a home system would be a pressuretrol or vapourstat. Some folks -- like me -- like to add a second, manual reset pressuretrol at a higher pressure as a safety backup.

You shouldn't have to whack a vapourstat to get it to reset. However, if they are set too low -- so that the cutout pressure minus the differential setting is near 0 -- they may not reliably reset. You could try simply raising the cutout pressure to see if it behaves.

Further, the newer ones -- without the mercury switch -- are known to be out of calibration sometimes. The only really reliable way to be sure is to pair it with a known accurate low pressure gauge, and set the cuout with that; your gadget may be sufficiently accurate to let you do that.

Knave72

Maybe I can answer my own question here...

It's a Dunkirk PVSB-7D and when I look under the hood I see 7 cast iron segments...or sections.

Knave72

There's also this table which gives me a clue...