Which Vaporstat to consider?

Boiler Talk

Here's a photo of the stuff I have right now.  The system cut off around 3 pounds.  It's oil heat.  What Vaporstat would be right?  0-16 OZ?  Please recommend that and how it should be wired.  Is wiring in a series the way it's done?  That seems easiest.  Thanks.  for you time.  I bet this was asked many times before. 

Rod

Vaporstats

Hi- You should be able to get your Pressuretrol to operate lower than 3 PSI. though at really low pressures (ounces) you will definitely need a Vaporstat.

    For a one pipe steam system the typical maximum for OFF is set at 1.5psi (no more than 2 PSI)  and subtractive diff of 1psi for ON at 0.5 psi. This is a good start point and you can experiment with trying lower pressure points/ How low you can go depends on the characteristic of the individual system.

Generally for a 1 pipe steam system the Model 1017 (0 - 4PSI) works best.  Some steam systems (mostly 2 pipe vapor) will run at even lower pressures so should use the Model 1009 (0-16 ounces)   The name of the game is to stay below 2 psi at absolute most, below 1.5 psi ideally.

Lower = Better!



The Model L408J comes in several configurations



The 1009 or 1017 are used for residential steam boilers.



The 1009`s scale is only in oz. ( 0 to 16 oz.)

 It has a SPDT switch to start the burner on pressure drop

.

The 1017`s scale is only in psi. (0 to 4 PSI)

It also has a SPDT switch to start the burner on pressure drop.



****************************************************************************

You also see the following L408J models listed. Ignore these and stay with the 1009 or 1017

The 1025`s scale is also in oz, but the SP switch only makes on pressure rise.

The 1033`s scale is in psi, and the SP switch only makes on pressure rise.

*******************************************************************************************

Links

Honeywell Link for 1009      (0 to 16 Oz (1.PSI ) 

http://customer.honeywell.com/honeywell/ProductInfo.aspx/L408J1009#ProductSpecification



Honeywell Link for 1017    ( 0 to 4 PSI )

http://customer.honeywell.com/honeywell/ProductInfo.aspx/L408J1017



The Vaporstat is wired in series with the other safety controls such as the LWCO.  You can use the Vaporstat as the normal pressure controller and the present Pressuretrol as a High Limit backup.

- Rod

malex

How accurate is the 0-4psi?

I have a one pipe and as long as I keep the temp steady I don't see more than an oz or two. But when I increase the temp by even one degree on a cold day the boiler goes on a long steam and the radiator vents go hay wire before the pressuretrol cuts out a 2psi (it is set to cut at .5+1 but I guess its off by .5psi).



I think my butter zone is probably around 12 oz (0.75psi). Is the 0-4psi vapor stat accurate enough in that range? Otherwise I may go with the 0-16oz but I would like the flexibility to go a little over 1psi if I need to. Any thoughts?

Jamie Hall

On one pipe steam

I think I'd go with the 0 - 4.  The 12 ounce to say 20 ounce range is well within the accurate (or to be more precise, precise) range of that unit.  The 0 to 16 ounce is fine -- indeed, really needed -- with vapour.

Boiler Talk

And the answer is?

Thanks guys.  Now all I have to do is buy the parts.



 I tried messing with the pressuretrol.  I am pretty sure it once cutout at 1.5 PSI, but I have not seen that performance again.  I tried turning the screw to the point where it almost falls out.  Someone else wrote he did this too and made no difference.  I don't see the 1.5 any more.  If I did I should be happy.  I wrote in another post about how the spring was not set properly.  I fixed it and I don't see the 4 pounds I recorded, but also don't see 1.5 either.  I wish there was some way to measure the psi on the lever in the Trol to see the actual PSI it would act.  Some sort of measure tool other than waiting for the system to run, you know what I mean?  LIke a scale that you just attach to it. 

Rod

Vaporstat Tester

Hi- Here’s a link to a post on Vaporstats that might be of help to you.  http://www.heatinghelp.com/forum-thread/128249/why-do-Honeywell-vaporstats-suck-so-badly



On this post there is an explanation by Gerry Gill, a very experienced Cleveland steam pro. on how to setup the ingenious Pressuretrol /Vaporstat tester he devised.  If you haven’t done so already, you also might want to take a look at his website  http://www.gwgillplumbingandheating.com/

as there is lot of great information on steam there.

- Rod

Boiler Talk

Latest Finding on P-Trol - lowering the switch

To gain a lower cut-in pressure I experimented with the pressuretrol again.  I thought the position of the micro switch might be part of the issue.  The switch is NOT fitted very well, so an adjustment of its position is possible.  I loosened the two HEX screws and found the switch could be lowered a lot.  I am waiting about a half hour to see if pushing the switch down toward the rocker enables a lower pressure.  I bet this trick will work.  Forget about the spring, try the switch! 

Boiler Talk

Latest Finding on P-Trol - lowering the switch

The cut-out pressure was a hair below 1 lb.  The cut-in was slightly above the zero.  I suppose that's all I really need.  It's a heck of a lot better than three pounds.