pressure-trol set wrong??

nicksxvs

my steam boiler cycles between 2.5 lbs and 3.5lbs.i have the pressuretrol turned as far down as it will go and the differential wheel down as far as it will go. when the boiler cycles it comes on at 2.5 and shuts off at 3.5. shouldn't it go lower before it comes on? i have another post about a relay and this is the same boiler i asked about last year.

SteamingatMohawk

Just to make sure, what is the full model number?

nicksxvs

neilc

is the pigtail clear ?

pecmsg

Is that a 0 - 30 gauge? It can’t read that low. 

nicksxvs

according to the gauge the pressure is only flutuating from 2 to 4 pounds i want to extend the time its off. i don't want to go above 4 pounds i'd like it to drop lower. right now its on 3 minutes and off 3 minutes 24-7.

ethicalpaul

looks like the pressuretrol isn’t set to the bottom of its scale

nicksxvs

i bottomed the screw, your right i need to check closer to see if it's hanging up. i'll probably be there monday.i tried to install a relay in line with the thermostat but it caused the zone valve to buzz. maybe it should be on the other wire going to or coming from the thermostat.

pecmsg

Gauges only read accurately in the mid-range.

Get a second gauge that reads 0 - 3 or 0 - 5#'s as an accurate reading.

NOTE: the 0 - 30 must remain on the boiler, required by code.

nicksxvs

thanks

EBEBRATT-Ed

@nicksxvs

Those pressure controls are the most common one in use and they are not accurate at all. You may be able to improve it somewhat. I just installed a new one and the best I could get is 2.5 cut out and 1.5 cut in.

Someone posted recently that Johnson /Penn controls has one that is better

nicksxvs

i guess it's doing it's best. the pastors new neighbor is a plumber and will take a look next week. he had a hvac guy last year and they charged a boat payment an hour each for two workmen.

reggi

@nicksxvs Nick... Pricing is against the forum rules if you can edit to Alot or something else.. ty

Is your boiler running? Why is holding 2 pounds if it isn't it should be at atmospheric 0 or below as you have a Compound Gage that is made to measure vacuum .. Sub atmospheric also..
It's difficult to see but it looks  like your gauge is bushed to the top of the boiler and irregardless it's probably fried by now and not functioning nearly as it should be..
Very easy to test.. (as the pigtail should be checked and cleared of any buildup anyway)
Remove the Gauge and it should go to 0
if not ..post here

Remove the pigtail ( it's exposed ) and check it for blockage or crud.. try blowing through it to get a feel for the resistance first.  . Then run hot water through it while pushing a large zip tie or firm wire through the loop ..then check back

It'll only be your time... Make sure the boiler isn't active when servicing it

nicksxvs

i cleaned the pigtail last year. it's holding at 2 lbs. because it's running. it goes up to 4 and then shuts off it quickly goes back down to two and turns on. i wish the pressure would hold for awhile and not cycle so quickly. but it is what it is.

pecmsg

nicksxvs said:

i guess it's doing it's best. the pastors new neighbor is a plumber and will take a look next week. he had a hvac guy last year and they charged a boat payment an hour each for two workmen.

Funny

My car mechanic charges more than me and I bring the problem to him.

nicksxvs

if i had his brains i would have a vacation home.

neilc

neilc said:

is the pigtail clear ?

what about the pigtail under the Ptrol?
that steel pigtail will clog sooner than the yellow one under the gage

SteamingatMohawk

General opinion on HH seems to be to go with a 0-4psig vaporstat if you have the $$, because the most common pressuretrol isn't very good in the low pressure range.

nicksxvs

https://www.ebay.com/itm/115208904249?_trkparms=amclksrc=ITM&aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=237209&meid=fe28f4bb6f74445984866d4d1926e4b8&pid=101113&rk=3&rkt=12&sd=154651908959&itm=115208904249&pmt=0&noa=1&pg=2563228&algv=DefaultOrganicWeb&brand=Honeywell&_trksid=p2563228.c101113.m2108 i guess this is what your talking about. this building has classrooms on the second floor. about 6-12' radiators that are turned off. the vaporstat would have to be set at both the turn on and off settings.

reggi

nicksxvs said:

i cleaned the pigtail last year. it's holding at 2 lbs. because it's running. it goes up to 4 and then shuts off it quickly goes back down to two and turns on. i wish the pressure would hold for awhile and not cycle so quickly. but it is what it is.

@nicksxvs
Ok so what your saying is that

it's "idling" at  2 lbs without a call for heat.. and isn't heating any of the "Zones" ?

At some point , perhaps a call for heat, it starts climbing until it gets to 4 lbs on the gage and then cuts out (shuts off)  and drops to 2 lbs ? Before it refires and if there's still a thermostat call for heat it repeats the cycle...Is that a fair assessment of the boilers functioning ?
AND when the boiler is turned OFF .. does the Gage eventually return to zero ??when turned off and cool If you crack a fitting open slightly does air release and the gage drop ?..
The Vaporstat is for low pressure systems and if sitting with 32 oz and cutting out at 64oz NOW I'm pretty sure the precision of a vaporstat might not benefit you immediately...
The closed radiators aren't helping your situation as the Steam generated is now more than the system can evenly distribute before the thermostat is satisfied which is the probable cause of the boiler pressure rise....No where to go.. so it starts pushing and compressing the steam/air as the radiators that are closed are still factored in the distribution from the boiler.. and the boiler is still making steam to heat them..

You should probably read this a couple times slowly as my logic is sound but I I'm @DanHolohan 🤓 when it comes to writing 

SteamingatMohawk

If you go to supplyhouse.com search for L408J1017, you can see copies of the submittal sheet which comes with the vaporstat. The only thing missing is that sheet does not tell you which is 0-16oz vs. 0-4psi. 1017 is 0-4psig.

For a safety device, I would lean toward a brand new, no scratches from a known reputable source. You might be better off getting a price from a local plumbing/heating supplier.

nicksxvs

reggi said:

nicksxvs said:

i cleaned the pigtail last year. it's holding at 2 lbs. because it's running. it goes up to 4 and then shuts off it quickly goes back down to two and turns on. i wish the pressure would hold for awhile and not cycle so quickly. but it is what it is.

@nicksxvs
Ok so what your saying is that

it's "idling" at  2 lbs without a call for heat.. and isn't heating any of the "Zones" ?

At some point , perhaps a call for heat, it starts climbing until it gets to 4 lbs on the gage and then cuts out (shuts off)  and drops to 2 lbs ? Before it refires and if there's still a thermostat call for heat it repeats the cycle...Is that a fair assessment of the boilers functioning ?
AND when the boiler is turned OFF .. does the Gage eventually return to zero ??when turned off and cool If you crack a fitting open slightly does air release and the gage drop ?..
The Vaporstat is for low pressure systems and if sitting with 32 oz and cutting out at 64oz NOW I'm pretty sure the precision of a vaporstat might not benefit you immediately...
The closed radiators aren't helping your situation as the Steam generated is now more than the system can evenly distribute before the thermostat is satisfied which is the probable cause of the boiler pressure rise....No where to go.. so it starts pushing and compressing the steam/air as the radiators that are closed are still factored in the distribution from the boiler.. and the boiler is still making steam to heat them..

You should probably read this a couple times slowly as my logic is sound but I I'm @DanHolohan 🤓 when it comes to writing 

i will read your post more thoroughly. idle? the boiler is turned on by a outside temperature switch when the outside temp. drops below 50 the boiler comes on. it then goes up to 4 pounds shuts off and turns on when it reaches 2 lbs. it does this until the month of May. or the outside temp. goes above 50. there are 2 zones which are closed until one of the thermostats is raised. thermostats are not connected to the boiler.

nicksxvs

i did a google search on vaporstats and more than one link sent me to this site. i have a lot to learn about pressure drop, distance from the boiler and steam traps. i'm going to assume i need to think in pounds instead of ounces because of the buildings size..i'm probably wrong or right twice a day.

nicksxvs

is a 4lb gauge big enough? i don't know how many ounces the building needs to reach all the rads.

reggi

nicksxvs said:

is a 4lb gauge big enough? i don't know how many ounces the building needs to reach all the rads.

Hmmm No.. Not if your pressure is 4lbs.. reason is you'd be Maxing it out (not good) and How would you know that the pressure isn't higher at some point than 4lb..

reggi

I understand now... From month November? Through May the Boiler will run 24/7 if the outside temperature is below 50° ..There are 2 thermostats that control 2 zone valves that work independent...
The boiler is running at 2 lbs ( your cut-in) and it's set to cut out at 4 Lbs..
Both thermostats and turned down and neither one is calling for heat .
The boiler is running...no steam is being sent through the mains so the steam pressure builds until it gets to your setting of 4 lbs then it cuts out...stops running and the pressure drops to 2 lbs , the boiler starts up and repeats the cycle.... over and over and over...
Now you want to lower the pressure perhaps to ounces ? or replace the controls so it is lower... So then in ounces...now your at 32 ounces cutin and 64 ounces cutout.. putting in a vaporstat will double no quadruple your on and off cycle so it will be doing what it's doing now 2-4 times more often...
Anyone feel free to jump in and correct me if I'm not interpreting this correctly
I don't believe this is what you want to accomplish..
I defer as I have no solution to this at this time... other than having the system hooked up appropriately by a skilled professional..

Edit.. Is there anything stopping you from opening the closed radiators and turning the thermostats up to open the valves and let the boiler run a unrestricted cycle so you can get a feel for how it runs and see what the pressure gauge moves to..if anywhere...? @nicksxvs

nicksxvs

yes, i could turn them on. maybe not today later this week.

ethicalpaul

nicksxvs said:

 i'm going to assume i need to think in pounds instead of ounces because of the buildings size..i'm probably wrong or right twice a day.

I think this is one of those wrong times. Keep thinking in ounces

neilc

how big is the building?
kidding,
it doesn't matter , , ,

Empire State runs on less than 2 psi,

Ptrol pigtail ?

nicksxvs

next time im there i can clean the pigtail

nicksxvs

did a test today. with one zone and half the radiators on. the burner comes on when the pressure drops to 1.5 psi. it runs for 2 minutes shuts off at 4 psi. it takes 3 minutes to drop to 1.5psi. 2 minutes on 3 minutes off. i open the other zone valve and turned all the rads. on to number 3 on there dials. now the pressure drops to .5 psi, the burner runs for6 minutes it gets to 4psi and shuts off. it takes 3 minutes to drop to .5psi and then on again. on 6 off 3.

Jamie Hall

The pressure drop is from condensing steam. Not much you can do about that. Nor, unhappily, with that type of control scheme is there much you can really do about the cycling. However, lowering the pressure will make everything in the building happier. It will also probably save fuel, as it won't have to fire so long to bring the pressure up to cutoff.

Is there any way so that the control scheme can be revised so that there is one zone which is always on, and the other turned on only when needed? Then you could control the boiler with the always on zone thermostat -- it would only run when heat was needed there -- and the other zone would get heat when it was needed there, provided the master zone was on?

nicksxvs

the pressuretrol is set as low as it will go. with both zones on and all the radiators on the pressure would drop to zero and the burner comes on. but with only one zone on and half the radiators closed the pressure drops to 2 lbs and the burner comes on again. there running a daycare from 6 am to 6 pm so one thermostat is calling for heat. the thermostats are not connected to the boiler only to the zone valves so having one on and open would have no or little effect on the boiler.

Jamie Hall

Your pressure control is set too high, whatever else may be going on. The boiler should never reach 2 psi, never mind 4 psi.

You may want to verify that with a known good gauge. You may want to clean the pigtail. If neither of those show a problem, and the pressure control can't be set lower, it's either the wrong control or it's junk.

Just letting the boiler run 24 hours per day just because it's winter really isn't a very good way to save fuel or money.

Is there a reason -- I presume there is or you would have tried it, so what is it -- that the boiler can't be controlled by the day care, and that zone valve left open? Then when the other zone valve opens (the sanctuary? Offices?) heat will be available to it, so long as the day care is warm. Another option would be to run the boiler off the end switches on the zone valves. There is some risk that one might call immediately after the other shuts off, but if there is a post purge/pre purge on the boiler that's not an issue.

nicksxvs

i'll clean the pigtail and get a 5lb gauge. i tried wiring a relay into the wires coming from the transformer 24 volt. the 120 side of the relay went to the outside temperature switch. when i turned the power i was hesitant but the boiler started to cycle on but one of the zone valves started to buzz so i shut it down. the transformer wires are sprial so maybe i connected to the wrong side, line or load, or the winding of the relay causes a buzz.the valves are probable $500.00 so i wasn't going to experiment with them.

Jamie Hall

make sure that you have the correct voltages!

nicksxvs

heres the valve and transformer. there are four valves total two valves on each thermostat.
there 12 feet up so its impossible to trace the wires

nicksxvs

heres the relay. i don't know anything about electronics, i just asked for a 24 volt.

Jamie Hall

That relay should work. The zone valves do need 24 VAC -- but they need enough of it. That transformer should be enough to power them

SteamingatMohawk

@Jamie Hall Please take a look at the first photo in this discussion. I can't tell if the pointer is really bottomed, but it looks like it isn't. I am curious if the gauge (stranded or solid) of the wires and the orientation could be affecting the action of the switch.

Jamie Hall

Way up there at the top, @SteamingatMohawk ? In that picture the pointer doesn't look bottomed to me, either. It should be set just above the bottom -- in my opinion anyway. Those controls with microswitches aren't affected much if at all by orientation, and the wires should be OK.