So, last year, I finally dialed in the PA404a using the technique we’re not aloud to say on TH-cam (😂) . It worked perfectly until I tightened the set screw on the cover. Seems the metal body flexes just enough to throw it off! My fix was to place the cover on and just put the set screw in one turn with a dab of lock tight on the tip! Works better than factory designed!
Thank you for reporting that putting on the cover will throw off the setting! That goes a long way to explaining why there were a few times that I'd tweaked the pressuretrol a low setting, only to get a no heat call back due the PA404A not resetting! I had put the cover back on, assuming all was well. So now I know that to really dial it in, the unit must be tested with the cover on from now on. Thank you again!
I have an old pressure control that was probably on the boiler before the current one in my house. It will move to the new boiler when I install it. It's a Perfex model 700D pressure control. Dead nuts accurate down to 0.75 psi cut out, which is as far as it goes. I see tons of them on Ebay new old stock for decent prices. They were sold under many names, Perfex, Timken, International Economy, General Control, etc. They came in many pressure ranges including a vapor/vacuum model. They are not a mercury switch or snap switch control, rather using points almost like a distributor on a car that have a magnet on the base. It's a difficult to describe design, but it works well. It's a bakelite cased control with an art deco style. You should pick one up and see how you like it, I find mine to be significantly more accurate than both Pressuretrols that I own. Search 700D pressure control or 700D steam control or just 700D control to find one. Timken Control should also get you some results. I've been searching for the Vapor model for quite a while because it seems it would work significantly better than the current Vaporstats.
Gordon, one has to wonder if these come out of the box set high so that we are forced to do (their) fine calibration work. I see too many in the wild from cheating and fooling companies were never adjusted. Here my own boiler (properly sized and almost no water use) never seems to hit the cutout, reaching 1/2 lb before t-stat cutout. Am I missing something? Thanks again.
Thank you for your comments. I think the factory set-up is supposedly to meet the UL listing and that seems to be more honored in the breach nowadays. Too many installers seem to think the control is set at the factory & that's that - they ain't touching it. Lucky you with the properly sized boiler! Properly sized (or even undersized "by the book" ie ignoring 1/3 pick-up factor), the steam output from the boiler should be totally absorbed by the piping & radiators and converted into water with little to no leftover steam to build pressure. Oversized boilers just keep hitting the pressure limit, sort of like driving your car with the gas petal held down & controlling the speed with the breaks.
What causes the sight glass tube to surge down and the low water shuts off the boiler. The water level bounces and shuts off the boiler. After a few minutes the water level returns and the boiler re-starts. I flushed the boiler and the wet return was cleaned in Sept. Pressuretroll is at 1lb and .5.
question, I have this same controller and my issue is that it takes too long to cut back in after the max pressure is reached. Can i just turn the screw, raise the cut in, ti solve this problem. Dont really want to bend anything inside.... Diff is at 1 and the cut in is bottomed out. (when i say it takes too long, I mean the radiator go almost cold all over the house before it cuts back in......and when it does, it doesnt stay on that long before cutting back out......HEat is clicked on, on the thermostat the entire time.)
@@gordonschweizer5154 thanks for the reply. Would screwing the pin safely help with the short cycles and long cut-in times, while I wait for a professional to check?
@@gordonschweizer5154 Thanks for the responses.... The problem is, I live is a big city and many are concerned only with getting that arrival fee and not with fixing anything.... I've been burnt many times. I think I will think about replacing the whole furnace when it gets a little warmer. This problem is only an issue on very cold days, when the heat is "on" for almost the whole day.... the furnace reaches the pressure and cuts off in about 30minutes..... then it takes about 3hrs or more for the pressure to go back down to where it can cut in again. And I've discovered that after about 3.5 hours....if I touch the cut-in screw at all, the furnace turns on and runs the normal 30minutes....before the cycle starts again.. Can you tell me if it is normal for it to take 3hours for the pressure to go down and allow the furnace to turn on? Even when I screw the screw to the point of turning on the furnace.....it does not affect how long it takes to cut back in. :-( I've been in my house for more than 20years and the furnace looks old when I got it..... shame to have to replace it when it is only used about 3 months in the year! but if it is less than 10k....I think I will just pull the trigger and be rid of this annoyance.....for a while.
Turn the power off to the boiler. Remove the wires to the p-trol. Take the p-trol off the pigtail. Blow into the pigtail to see if it is clogged. If it is, replace (or clean out) the pigtail, (not the whole boiler!!!!) Put new (or cleaned) pigtail back. Thread the p-trol back onto the pigtail. Hook the wires back onto the p-trol Turn the power back on.
On a large-building boiler system, have gone through 4 new L404F 1060 units, all of which won't cut-on at the MAIN minus DIFF pressure level. Finally had one 'working' last year by reducing the DIFF setting relative to the MAIN, but when firing up boilers this fall, it won't work again. Just purchased an old 404F 1060 unit off eBay, which I expect will work just fine. Total nonsense.
Thank you for sharing your story. Please make sure your pigtails are totally clear. But, yes, while the L404F 1060 units certainly *look* impressive when compared to the humble PA404A pressuretrol, they don't work nearly as well, IMHO. I would consider using that instead of the L404F. While I rag on the 404 a bit, they are at least easily tweakable.
So, last year, I finally dialed in the PA404a using the technique we’re not aloud to say on TH-cam (😂) . It worked perfectly until I tightened the set screw on the cover. Seems the metal body flexes just enough to throw it off! My fix was to place the cover on and just put the set screw in one turn with a dab of lock tight on the tip! Works better than factory designed!
Thank you for reporting that putting on the cover will throw off the setting!
That goes a long way to explaining why there were a few times that I'd tweaked the pressuretrol a low setting, only to get a no heat call back due the PA404A not resetting!
I had put the cover back on, assuming all was well.
So now I know that to really dial it in, the unit must be tested with the cover on from now on.
Thank you again!
I built a bench tester for setting new pressuretrols, I’m amazed at how out of wack the mechanisms are.
I have an old pressure control that was probably on the boiler before the current one in my house. It will move to the new boiler when I install it. It's a Perfex model 700D pressure control. Dead nuts accurate down to 0.75 psi cut out, which is as far as it goes. I see tons of them on Ebay new old stock for decent prices. They were sold under many names, Perfex, Timken, International Economy, General Control, etc. They came in many pressure ranges including a vapor/vacuum model. They are not a mercury switch or snap switch control, rather using points almost like a distributor on a car that have a magnet on the base. It's a difficult to describe design, but it works well. It's a bakelite cased control with an art deco style. You should pick one up and see how you like it, I find mine to be significantly more accurate than both Pressuretrols that I own. Search 700D pressure control or 700D steam control or just 700D control to find one. Timken Control should also get you some results. I've been searching for the Vapor model for quite a while because it seems it would work significantly better than the current Vaporstats.
Gordon, one has to wonder if these come out of the box set high so that we are forced to do (their) fine calibration work. I see too many in the wild from cheating and fooling companies were never adjusted. Here my own boiler (properly sized and almost no water use) never seems to hit the cutout, reaching 1/2 lb before t-stat cutout. Am I missing something? Thanks again.
Thank you for your comments.
I think the factory set-up is supposedly to meet the UL listing and that seems to be more honored in the breach nowadays.
Too many installers seem to think the control is set at the factory & that's that - they ain't touching it.
Lucky you with the properly sized boiler!
Properly sized (or even undersized "by the book" ie ignoring 1/3 pick-up factor), the steam output from the boiler should be totally absorbed by the piping & radiators and converted into water with little to no leftover steam to build pressure.
Oversized boilers just keep hitting the pressure limit, sort of like driving your car with the gas petal held down & controlling the speed with the breaks.
What causes the sight glass tube to surge down and the low water shuts off the boiler. The water level bounces and shuts off the boiler. After a few minutes the water level returns and the boiler re-starts. I flushed the boiler and the wet return was cleaned in Sept. Pressuretroll is at 1lb and .5.
Is this a new install?
question, I have this same controller and my issue is that it takes too long to cut back in after the max pressure is reached. Can i just turn the screw, raise the cut in, ti solve this problem. Dont really want to bend anything inside.... Diff is at 1 and the cut in is bottomed out. (when i say it takes too long, I mean the radiator go almost cold all over the house before it cuts back in......and when it does, it doesnt stay on that long before cutting back out......HEat is clicked on, on the thermostat the entire time.)
I would have your "pigtail" checked to make sure it isn't clogged first
@@gordonschweizer5154 thanks for the reply. Would screwing the pin safely help with the short cycles and long cut-in times, while I wait for a professional to check?
@@rayjgold I am reluctant to recommend any other course of action until the pigtail is checked.
@@gordonschweizer5154 Thanks for the responses.... The problem is, I live is a big city and many are concerned only with getting that arrival fee and not with fixing anything.... I've been burnt many times. I think I will think about replacing the whole furnace when it gets a little warmer. This problem is only an issue on very cold days, when the heat is "on" for almost the whole day.... the furnace reaches the pressure and cuts off in about 30minutes..... then it takes about 3hrs or more for the pressure to go back down to where it can cut in again. And I've discovered that after about 3.5 hours....if I touch the cut-in screw at all, the furnace turns on and runs the normal 30minutes....before the cycle starts again.. Can you tell me if it is normal for it to take 3hours for the pressure to go down and allow the furnace to turn on? Even when I screw the screw to the point of turning on the furnace.....it does not affect how long it takes to cut back in. :-( I've been in my house for more than 20years and the furnace looks old when I got it..... shame to have to replace it when it is only used about 3 months in the year! but if it is less than 10k....I think I will just pull the trigger and be rid of this annoyance.....for a while.
Turn the power off to the boiler.
Remove the wires to the p-trol.
Take the p-trol off the pigtail.
Blow into the pigtail to see if it is clogged.
If it is, replace (or clean out) the pigtail, (not the whole boiler!!!!)
Put new (or cleaned) pigtail back.
Thread the p-trol back onto the pigtail.
Hook the wires back onto the p-trol
Turn the power back on.
On a large-building boiler system, have gone through 4 new L404F 1060 units, all of which won't cut-on at the MAIN minus DIFF pressure level. Finally had one 'working' last year by reducing the DIFF setting relative to the MAIN, but when firing up boilers this fall, it won't work again. Just purchased an old 404F 1060 unit off eBay, which I expect will work just fine. Total nonsense.
Thank you for sharing your story.
Please make sure your pigtails are totally clear.
But, yes, while the L404F 1060 units certainly *look* impressive when compared to the humble PA404A pressuretrol, they don't work nearly as well, IMHO.
I would consider using that instead of the L404F.
While I rag on the 404 a bit, they are at least easily tweakable.