pressure gauge

danoer1

Is it a concern that the analog pressure gauge mounted on top of the LWCO does not ever budge? The pressure setting is .5 cut in with 1 as the differential, and the gauge I am talking about is mounted right next to the Honeywell box where you set the cut in pressure.



thanks,



dan

Jamie Hall

Probably not

a problem -- if that is a 0 to 30 psi gauge (which is required by code).  Those gauges are none to accurate in the low pressure ranges that residential systems operate at (yours seems to fine, by the way!) and it's not a bit surprising that it doesn't budge, or just maybe moves just a little, right about when the system shuts down on pressure (if it does).

nicholas bonham-carter

gauge problem

yes, it is a problem not to have a gauge which can accurately measure the pressure of the system-especially the back-pressure of the system as the air is escaping through the main vents.

this is like having a home-built car with a speedometer from an old fighter plane whose top speed is 2000 mph. when you are driving slightly above the speed limit, the needle would not even move! how will you explain that to the judge?--nbc

danoer1

new gauge? 0 to 5 psi or so?

So solution might be to put in a new gauge that is of a lower overall range? Source?

Jamie Hall

Can't just put in a new gauge

if you really want to see the low pressure, you have to put in an additional gauge.  The 0 to 30 psi gauge is required by all the codes I've seen; it has to be there.  If you do want to do it, though, you can put a 0 to 5 or 0 to 3 on as well.  I'd have to look at how your present setup is piped, but each gauge (and the pressuretrol) should be on its own pigtail, but they could all come off the same gauge manifold if you wanted to.

Steve_175

Pigtails

I have been looking to add a low pressure gauge as well. BobC sent me this pic on another thread. Is his set up ok or would he need pigtails as well?

Jamie Hall

That works...

but I'd still like to have pigtails on there... but then, I'm a belt and braces boy myself.

Johnny13

Same as in town?

Last year I saw someone had a pig tailed rig with a low pressure gauge attached at the vent point on the radiator. Is this accurate for monitoring the pressure of the system, or is on the boiler the most appropriate for seeing what is going on?

jpf321

good question ...

i'd like to hear thoughts on this as well .. the first thing that would be a requirement on the "rad" location is that that rad has it's vent closed .. also the "condensation vacuum" effects of the rad may affect the reading ..



i would still believe the best place is boiler since it's the single "blow" point reaching out to all corners (hopefully) of the system .. 

Johnny13

Reason why

My 0-30 gauge is malfunctioning, and I am nervous about the idea of changing it myself. It connects on the back of the gauge, and that is flat against the body of the boiler. I am not so worried that my pressure is too high, tho I will replace it. In the meantime I am hoping to get something like I described going so I can look at what is happening without having to go down 2 flights of stairs.



Also, I know a 0-30 gauge is code, but it seems like a 0-10 or 15 would be more helpful if I am going to the trouble of replacing it. I can't see how this would be dangerous since I would shut things down if they reached 10. Are there surprise boiler inspections I need to be worried about if I use a non approved gauge?

haaljo

just install two gauges on brass pigtails

one at 30 one at 3 pounds. Don't mess with the one on the boiler. The one you will look at all the time will be the 3 pounder.

Jon Held_2

Control Menorah

This is how I set mine up. The gauge is 0-20 oz/in. Vaporstat cuts out at 10oz; cut in at 4. With the blower purge delay, the pressure will go slightly negative until the burner fires again.

I never really understood the need for a 0-30psi gauge. I'm trying to heat my home, not move it down the street.

jpf321

lmao

that's funny

Brian_74

It's was funny

but as Jamie pointed out above, the 30psi gauge is required by code.



What did you use on the threads? It looks yellowish.

Oak Park Electric

What's with the 30?

Residential boilers tend to be rated at 30 or 50 PSI for hot water, and 15 PSI for steam.  The reason is that 15 pounds is the breakover point between "low "and "high" pressure for steam systems.  Plumbing / heating / mechanical codes want one gauge on the unit that has a range of twice the relief valve pressure.  Not  "you must have a 30 PSI gauge", but instead  "you must have a gauge with a scale that is double the relief rating ".  So the boiler is rated 15, and consequently so is the relief valve.  Do the math.  That is why we have 30 pound gauges.  If you really like safety, make a Menorah with a 3 PSI gauge and a vaporstat on one side, and the 30 PSI gauge and original pressuretrol on the other.  Wire it and set it so that the pressuretrol is a high limit, in case the vaporstat doesn't open when it should.  Use a tee with two pigtails (brass, of course ) and if you can find 1/4 brass pipe and fittings, make the whole body of the Menorah brass too.