Can I put a pressure gauge at the end of my main run?

slapp

Trying to balance the system in my new house, it has clearly been neglected for a number of years. the boiler doesn't have a pressure gauge near the pressuretrol, so I am putting one in there. I want to put one at the end of my main near the large vent for sanity. Is there a proper way to do it, or can I just tee off of the main vent? I plan on just a 0-10 PSI for both. Pic attached

Captain Who

I definitely wouldn't go any higher than a 0-3psi gauge myself. I don't know of anybody who has put one at the end of the main but there's no reason why you can't. I believe you would need a pigtail or a 18" nipple to protect it from the heat. The pressure there should be slightly less than at the boiler but only by whatever the piping pressure drop is......probably only on the order of an ounce.

slapp

Thanks for the input, I supposed you are right, why go to 10 when I know it should never be even close to that AND the pressuretrol would cut out at 5 anyway. I think I will go the pigtail route since I have one around, thanks for advice on keeping it from the heat.

slapp

You are right...since moving into this house I am just not sure that the system is typical yet. By that I mean, I am looking for sure fire ways to find out if it is designed and sized right since I have my doubts. I guess my thought here would be if I sat there when the boiler turned on and waited until the pressure rose and stabilized I would know how long it took to fill the main. For some reason I don't trust the vent on the end of the main since I can't prove it is working in top order.

Figured I would start with the main before trying to trouble shoot radiators since that seems to be the theme around here.

Captain Who

For trying to ascertain when the steam hits the end of the main, I'd think it would be much better to have a thermowell with a temperature sensor. When the vents close it will start to register as pressure at the gauge on the boiler practically instantaneously.

BobC

On my system the main is full of steam when the 0-3PSI gauge just starts to quiver, steam moves at very little pressure as long as the air gets out of the way.

Bob

slapp

I performed a slightly modified version of Hatterasguy's technical test.

I have 110 feet of Main, on the end is a Hoffman 74.

It took 20 minutes to heat up to where I couldn't touch it...I never heard the "tink" that the vent closed. Not sure if these do that, or only the smaller radiator ones do.

So...Fast enough?

jch1

@hatterasguy what do you do to determine when steam has reached the header? Watch the sight glass for height fluctuations?

slapp

@jch1 I am pretty sure he is going to tell you to use your hand...see above...

KC_Jones

How do you like your hand? Medium rare?

jch1

Haha thanks guys. I just figured there may be a way to determine this without requiring manual intervention. I'll have to wait until everything is cooled down sufficiently to time this.

Tim_64

I have a gauge on the last radiator on the longest main in my house... which happens to be within view from my Man Cave and living room couch....

When I hear the burner rumble to life......I'll check the gauge 20 minutes later....... If it is showing pressure.... life is good....

Just tee'd it in before the vent...

vaporvac

I thin you're all getting a little "Slapp" happy here!
Anyway, you mention:

slapp said:

since moving into this house I am just not sure that the system is typical yet. By that I mean, I am looking for sure fire ways to find out if it is designed and sized right since I have my doubts.

Have you measured your rads yet and compared their EDR to that of your boiler? That's the only way to know if your system is sized correctly. Some pics of the rads and near boiler piping would help diagnose your system. 20 minutes is crazy slow...It seems almost not possible. My 150ft main get heat to 125ft point in @ three minutes after the header gets hot. Were you timing from a cold start or after steam was in the header?
Colleen

slapp

@vaporvac I measured all the radiators in the house and got an EDR of 370. I have a mix of cast iron baseboard and 12in deep x 12 in high radiators pictured. I didn't find an exact EDR value on any sheets for the 12x12 online, so I estimated 2.5 from others. My Burnham Independence IN-5 spec sheet says 140MBH Input, DOE 115, IBR Steam 86, and EDR of 358. The 370 to 358 is clearly tight and not in my favor. I also agree that the 20 minutes is not right. Which is why I think the Hoffman 74 is no good. The test was when the header heated up and the end of the main boiled my hand off.

@Hatterasguy‌ If I make a tree of Gorton #2's on the end, right now I have a 3/4 in opening, I am assuming that it is ok to reduce that for the 1/2 Gorton #2?

BobC

If there is a chance you will need more than 2 of them on one main, pipe the antler header in 3/4" and reduce down for each vent.

Bob

Captain Who

Just checked my 36ft, 2" main and it was 4min from the time the header was too hot to palm to the time last rad takeoff was the same. This is with just one Gorton #1 at the end of the 36ft, 1-1/4" dry return. So I guess my varivalves on the radiators are doing most of the venting work rather than the small vent on the return. I already knew that but just wanted to verify that I was OK, even though I'm violating the rules of slow vents on the radiators being preferred. I did the test with the system dead cold after an overnight setback of 53 F where the system didn't run all night at all as verified by cold pipes and gas meter unchanged.

Fred

"I measured all the radiators in the house and got an EDR of 370. I have a mix of cast iron baseboard and 12in deep x 12 in high radiators pictured. I didn't find an exact EDR value on any sheets for the 12x12 online, so I estimated 2.5 from others. My Burnham Independence IN-5 spec sheet says 140MBH Input, DOE 115, IBR Steam 86, and EDR of 358. The 370 to 358 is clearly tight and not in my favor."

I wouldn't be at all worried about this small difference in sizing. You are in great shape as far as EDR. Boilers have an average of 30% more EDR that's not shown on the rating plate. It's called a Pick-up Factor to allow for heating the Header, all the Mains and radiator run-outs from a cold start. If your Mains are insulated, you aren't using all of that built-in overhead.

misterheat

Now i want a radiator gauge !

slapp

Ahh, thanks for not closing this thread, as I owed everyone some partial closure. Two kids just doesn't allow for time to run these tests.

With the Gorton 2 tree, I now have the 110 foot main heating up in about 8 minutes, so that definitely helped. I notice that if I take one off and shake it, water drips out. Does that mean I didn't make the tree long enough? or is that just natural?

Now onto the original question, I put two 0-3 PSI gauges on the system, one on the boiler itself (took out the 0-30 gauge), and one on the end on a leg of the gorton tree. Been checking the gauges for the past 2 days....nothing...the one on the boiler, barely moves maybe every 20 second...jumps to .05 and then back to the needle stop.

I also ran a test where I turned the system off and let it cool just to see how long it would take to heat up from a larger setback. (Note I didn't tell the family and they weren't too happy to wake up to 55 degrees. The sad reality is that it took 15 hours to heat back up to 66 degrees. All the radiators have new Heat-timer Varivalves, the hot rooms are in the closed position and the cold rooms and large radiator rooms have it open and they still won't get hot enough. I even ran an experiment where I took off the vent on one of the radiators that never gets hot and it still performed the same.

So here is my conclusion, either the boiler is undersized, or it might not be getting enough gas pressure. I am having my plumber from my old house come next week to look at my EDR calculation and to check the pressure coming from the street and at the boiler when other appliances are on.

So that is it, unless anyone has any other comments or ideas. I appreciate all the help. BTW, I included a picture of the boiler and piping, should I insulate the header? All the way down to the boiler?

Fred

Put the 0-30 PSI gauge back on the boiler. You can have as many other gauges as you'd like on the boiler but local codes require the 0-30 PSI gauge. Go figure!

slapp

Ok, will do, I have a spare tee...thanks for the information, I did read that in another thread here...

Captain Who

Especially with the uninsulated near boiler piping and excessively long runs up to the main, that undesireable bull Tee could allow wet steam up into your main. I'd definitely insulate the ____ out of it and see what a difference you get. The near boiler piping is a bit wacky.