Gas Chain Troubles: Simmer Only

jpf321

I'm trying to assist a friend of mine to troubleshoot his gas train.
He has a Maxitrol RV53 and a Honeywell V88A, they are hooked up to Baso L62AA-5 Safetys.

• The pilot is lit.
  
• All the flutes have a small blue flame upon call for heat. The emphasis on SMALL.
  
• I have opened the Maixtrol cap and tightened down on the "PLATED" spring, --- no change.
  
• I have checked the voltage at the solenoid on the V88A .. 24VAC
  
• I have removed the bleed valve tubing on the V88A .. --- no change
  
• The solenoid is very WARM to the touch
  
• I do hear the audible click of the solenoid at call for heat.
  
• I have NOT put a manometer on the line.
  
• 
  

We are going to 1st attempt to replace the solenoid as that seems to be least invasive.

Last season, this was a roaring beast, now, a small simmer.

Pictures are here: https://photos.app.goo.gl/k5kTvmjuqrLfuz7VA
Documentation is here:
V88A: https://s3.amazonaws.com/s3.supplyhouse.com/product_files/V48A,F,J,V88A,J-User6.pdf
L62AA: https://s3.amazonaws.com/s3.supplyhouse.com/product_files/L62AA-5C - Use.pdf
Maxitrol: https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Maxitrol-RV53-1-Brochure.pdf

Any thoughts?

THANKS

JUGHNE

Sounds like low gas pressure. Is this LP or NG?
Should check pressure on both sides of the regulator. IMO

jpf321

NG from utility service (NY Metro NationalGrid) ..

I suppose I should get and include a picture of the gas service connection where it's brought into the house. I agree that it also sounds like low-pressure.

And there was "a bunch of work" done in the gas service room during the summer, but I can't see where it would have been turned down or restricted.

Could they have restricted it at the street valve? They replaced all NG infrastructure on this city block during the summer as well.

JUGHNE

Any other appliances connected to this service?
Is it a pounds or ounces system in the basement/house?

jpf321

updated photos linked above with GAS ROOM photos.

jpf321

uploaded annotated GAS ROOM pics.

Yes, there is a DHW Gas Fired Tank appliance fed from the same line, but it was not firing during my troubleshooting. There are no other appliances on the line.

Frankly, I don't know if it's lbs or oz system. But All the equipment is "original" nothing has been added or swapped out in several years.

The utility company did come and "Calibrate" the "Boiler Meter" shown in the pictures, during the summer. I do not know what tweaking that entails. That meter has a running value for Temperature corrected and non-corrected flow.

Additionally, the customer was on "lockout" due to "leak" in the meter room for about a week, some of the meter room piping is new, but I don't believe anything was downsized. But they did have utility company inspector sign off on the work and unlock.

FYI, the inspector shut down the boiler supply valve (at the boiler) valve since that would not light properly (the "simmer" problem we are currently troubleshooting).

Needless to say there was someone monkeying around the supply pipes both at the street (infrastructure replacement) and in the meter room.

At this time, do you feel that the gas train equipment is probably not at fault?

JUGHNE

Until the gas pressure can be measured on the inlet and outlet of the boiler gas regulator, you are just guessing.
If the pilot light looks good then you might have good pressure to the boiler.
IIWM, I would defer to someone who can measure pressures.

jpf321

thanks .. will post updates as they present

jpf321

i updated pics in the album linked above .. i include 1 of the pictures in this post to show where I measured the pressure from (the pilot valve) .. i'm not sure if that silver thing is also a regulator, if that's a poor choice of places to draw a reading from, I'll find another port ....

using a water tube at that location, i measured 7"WC ..

there are no markings on this old Bryant Boiler that spec the min inlet pressure. maybe it's in Dan's Beacon Boiler Ref -- no, the spec is not there.

the iTRON regulator serial number plate in the meter room shows "6 IWC" as it's out pressure with a "LT GRN" Main Spring.

there is a metal tag stamped on the street inlet before the 1st main valve which states SYSTEM PRESSURE 15 PSIG with EFV, and there is an EFV installed.

at this point, you may tell me to measure the pressure at the maxitrol .. that will involve taking apart quite a few pipes.

jpf321

i updated with more pictures of the meter room equipment
Pictures are here: https://photos.app.goo.gl/k5kTvmjuqrLfuz7VA

i measured the pressure at the pilot valve (picture below) to be 7"WC
i noticed the itron regulator in the meter room is stamped with 6 IWC output pressure
i noticed that there is a metal tag on the street pipe that says system pressure 15 PSIG EFV (excess flow valve is installed)

if I indeed need to measure from a point other than that pilot valve, for example at the actual maxitrol regulator, then it would involve significant piping disassembly which i'm not up for right now.

Steamhead

Can't tell from the pics- what is the BTU input on that boiler?

mattmia2

Is there another tap opposite the tap for the pilot regulator before the manual valve where you can measure the supply pressure? Can you take an overal picture that shows how all the valves and regulators are connected? It seems without adding pressure taps after the main valve and after the regulator or putting those devices in a test rig there isn't an easy way to determine which is the problem.

jpf321

@SteamHead -- good to hear from you once again old friend .. According to the Boiler Plate (I've added to the pics) .. It's a Bryant Mfg 443 - 9 and has a firing rate of 594,000 BTU Steam EDR of 1,980

@mattmia2 -- There are no other ports anywhere. I don't have any wide-angle pics at the moment, I'll ask my friend to snap a couple. The best I can do to get a "clean" supply side reading without unpiping too much is to break the union at the DHW which is branched from the same supply and has no other apparatus on it except the shut off. I'll only do that if you say that the reading from the pilot gizmo may be reduced due to that gizmo. But no, there are no ports on the boiler gas chain piping.

ScottSecor

I am reluctant to comment as I feel this work should be done by a professional that is very familiar with working on light commercial gas boilers and gas piping. That being said, let's keep it simple so no one gets hurt.

Give the boiler a call for heat, make note of the main flame height (yes, I know tiny). While the boiler main flame is on, cycle the gas fired water heater. Does the boiler main flame change in size or shape? Does it appear the at the main flame on the boiler is getting even smaller when the water heater is operating? If so, it may not be a boiler gas train problem but a incoming gas problem from the utility.

My guess is that the ancient gas train on the boiler needs upgrading as there are almost no modern safeties in place. I'm pretty certain that gas train setup has not been produced in over thirty years.

JUGHNE

If you look at the spec sheet you posted here for the gas valve,
There is a square head 1/8" plug for pilot connection.
That would be the incoming pressure to the gas valve after your pressure regulator.
The pilot is not connected there in this case because it is better on its own regulator and also one usually wants to operate the manual gas valve for testing/troubleshooting procedures.

mattmia2

What does that 1/4" tubing that goes between the regulator and the valve and goes somewhere to the burner do? (I am in no way making suggestions, I am just curious how it works myself since the pilot is fed from tubing from a regulator before the main manual valve).

You do need to check the incoming pressure while it is firing, if that is dropping under flow because the new distribution is not right then it will underfire.

jpf321

@ScottSecor -- i'm in agreement with you on all points. exactly why i was really only reporting easily acquired info and extremely reluctant to open up any more pipes than the pilot port. I will perform your DHW + Boiler test and report back. They are already in the midst of calling the Lic. plumber who performed the meter room pipe replacement work to see what light he can shed on things.

Thanks for everyone's comments. I'll let you know how it is resolved.

mattmia2

Another thing I just thought of, it is possible it was set up for distribution that was more than 4-5" at the appliance and has orifices on the burner that are sized for a higher pressure out of the regulator.

JUGHNE

FYI, the 1/4" tubing bleeds off the reg and gas valve diaphragms.
Any gas passed is sent into the burner chamber to be burned away or pass by gravity up the flue pipe.
Some places require that to be piped to the outside of the building.

mattmia2

Oh, ok, those are just the vents from those devices.

jpf321

thanks everyone ..

@Juhgne -- I did see that square port, i didn't think to measure there, my bad. From the language which you use above, that "gizmo" is some sort of pilot regulator .. so a reading there may be inaccurate it seems.

@mattmia2 -- there's an excellent, somewhat verbose, video on the operation of a gas regulator and explains the vent ports and why they exist. https://www.youtube.com/watch?v=n4DDnoMAHY8 -- in fact this guy's got videos on how nearly everything works. .. The vent port on the main-valve is described in the manual for the V88A .. it's really interesting how that one works. Linked above and here: https://s3.amazonaws.com/s3.supplyhouse.com/product_files/V48A,F,J,V88A,J-User6.pdf

@ALL -- the Lic. Pro is coming in tomorrow. I've been promised to be kept in the loop..

my guess is that some grit/dirt/etc lodged in the gas chain regulator especially due to the meter room piping work performed over the summer .. why it didn't end up in the dirt leg, or the NG dryer or the DHW, i won't have an answer.

maybe it was grit introduced by shutting the boiler manual valve which was shut during the piping work and inspection. maybe that's why it only went to the boiler equipment and not the other appliances... again why didn't it end up in the dirt leg of the boiler .. dunno.