Boiler fill valve, leave open, or leave closed?

 
User avatar
swyman
Member
Posts: 2355
Joined: Mon. Apr. 13, 2015 9:50 pm
Location: Blissfield, MI
Stoker Coal Boiler: Axeman-Anderson 260M Leisure Line AA-220 Boiler (FOR SALE)
Coal Size/Type: Lehigh Pea

Post by swyman » Sat. Jan. 27, 2018 11:31 am

bradludwig wrote:
Sat. Jan. 27, 2018 10:27 am
The book pumping away describes the senerio where location of pump and location of fill pipe can result in pressure increase over time. I am having this issue now so I have shut off fill valve until I repipe again. Should have bought book first!
I had this issue when my boiler was 200' away from where my fill valve was. Pressure was all over the place so like you I set it to where I wanted it and shut it off. Now I have relocated it and put it where they instruct you in the book, my fill valve stays on and pressure is always perfect!

 
User avatar
pintoplumber
Member
Posts: 371
Joined: Tue. Mar. 31, 2015 8:44 pm
Location: Lititz PA
Hand Fed Coal Boiler: Burnham number series 17
Other Heating: Oil, forced hot air. Rheem

Post by pintoplumber » Sat. Jan. 27, 2018 11:33 am

The scenario I heard was an oil burner not shutting off. The pressure increases to 30 lb and the relief valve lets pressure out and closes at 28 psi. No water is added because the pressure is up. This keeps happening until there is no more water in the boiler. Pressure is still at 28 so water can’t enter. Burner is still running. Finally pressure drops enough to let water in. Boiler could be red hot at this point and explodes with in coming water.

 
User avatar
swyman
Member
Posts: 2355
Joined: Mon. Apr. 13, 2015 9:50 pm
Location: Blissfield, MI
Stoker Coal Boiler: Axeman-Anderson 260M Leisure Line AA-220 Boiler (FOR SALE)
Coal Size/Type: Lehigh Pea

Post by swyman » Sat. Jan. 27, 2018 11:34 am

lsayre wrote:
Sat. Jan. 27, 2018 10:33 am
Two negative things initially pop into my mind regarding what can happen if it fails:

1) Boiler over pressures and pops the relief valve. This one would be quite easily recognizable.

2) Boiler very slowly seeps its absolutely filthy (and potentially chemical ladened) water into the homes DW supply over time, but no one ever recognizes it because at the same time the auto-fill system is actually keeping the fill pressure where it should be.
Boiler pressure is only 15psi (mine anyway) and DHW is 60. If there was a leak the DHW system pressure would pressurize the boiler.

 
User avatar
swyman
Member
Posts: 2355
Joined: Mon. Apr. 13, 2015 9:50 pm
Location: Blissfield, MI
Stoker Coal Boiler: Axeman-Anderson 260M Leisure Line AA-220 Boiler (FOR SALE)
Coal Size/Type: Lehigh Pea

Post by swyman » Sat. Jan. 27, 2018 11:40 am

pintoplumber wrote:
Sat. Jan. 27, 2018 11:33 am
The scenario I heard was an oil burner not shutting off. The pressure increases to 30 lb and the relief valve lets pressure out and closes at 28 psi. No water is added because the pressure is up. This keeps happening until there is no more water in the boiler. Pressure is still at 28 so water can’t enter. Burner is still running. Finally pressure drops enough to let water in. Boiler could be red hot at this point and explodes with in coming water.
We had a 2 million BTU steam boiler gas valve stay on and boiled all the water out of the system when I was going through my apprenticeship. I was not on the shift at that time but the supervisor tried to manually turn on the water valve to get water into the boiler...thankfully he was unsuccessful as the boiler company said he would have blown the whole city block up. It was very impressive how it melted all the heat tubes! We had 2 of those boilers as they fed a very large manufacturing plant.


 
User avatar
lsayre
Member
Posts: 21781
Joined: Wed. Nov. 23, 2005 9:17 pm
Location: Ohio
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Lehigh Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75

Post by lsayre » Sat. Jan. 27, 2018 11:52 am

pintoplumber wrote:
Sat. Jan. 27, 2018 11:33 am
The scenario I heard was an oil burner not shutting off. The pressure increases to 30 lb and the relief valve lets pressure out and closes at 28 psi. No water is added because the pressure is up. This keeps happening until there is no more water in the boiler. Pressure is still at 28 so water can’t enter. Burner is still running. Finally pressure drops enough to let water in. Boiler could be red hot at this point and explodes with in coming water.
If the system can't refill even with the valve open, this would be a good case for leaving the fill valve closed, would it not?

Makes me glad to have a LWCO that kills power when water falls below its level (which in my case is actually about 2" above the boiler).

In the mean time I have re-opened my valve after about two hours with it closed.

 
User avatar
Rob R.
Site Moderator
Posts: 17980
Joined: Fri. Dec. 28, 2007 4:26 pm
Location: Chazy, NY
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Chubby Jr

Post by Rob R. » Sat. Jan. 27, 2018 12:09 pm

I always leave mine open. I also have a second high-limit aquastat to hopefully avoid any extreme temperature situation.

 
User avatar
McGiever
Member
Posts: 10130
Joined: Sun. May. 02, 2010 11:26 pm
Location: Junction of PA-OH-WV
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Hand Fed Coal Boiler: BUCKET A DAY water heater
Hand Fed Coal Stove: Warm Morning 414A
Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
Other Heating: Ground Source Heat Pump and some Solar

Post by McGiever » Sat. Jan. 27, 2018 12:40 pm

Rob R. wrote:
Sat. Jan. 27, 2018 12:09 pm
I always leave mine open. I also have a second high-limit aquastat to hopefully avoid any extreme temperature situation.

Yes, This is what I advocate always. Having only a dump zone and/or a LWCO as a final saftey is still weak when, as with the failues already mentioned here clearly shows that what is really needed is a reliable dedicated automatic burner kill switch.

Then hope you never need it. ;)

 
User avatar
franpipeman
Member
Posts: 689
Joined: Fri. Jan. 11, 2008 4:27 pm
Location: Wernersville pa
Stoker Coal Boiler: efm 520 stoker fitzgibbons pressure vessel
Hand Fed Coal Stove: harman, russo
Coal Size/Type: rice
Other Heating: alpine propane condensing boiler radiant floor

Post by franpipeman » Sat. Jan. 27, 2018 6:33 pm

One of the biggest Catastrophe during my working career was flooding a brand new plastered three story building that was ay least 50 yards long. I Left the water make up on for the two cleaver brooks boiler., we had hydro tested for some time WE had a flame failure overnight and the damper for air handler didn't close the outside air dampers and freeze stats did not stop the fans as it was the first era of digital controls being used. Multiple coils froze that thawed and a massive flood with inches of water on newly carpeted floor. No-one was very happy . Ever since that day i do not leave water make ups auto fills on. Water flowed from the first floor down to the first from broken coils that ran for hours. No one stayed overnight to baby sit things.


 
User avatar
coalkirk
Member
Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Sun. Jan. 28, 2018 10:17 am

Auto fill open always. I also have a low water shut off and a backflow preventer. It's fine to say " I monitor my system everyday and make adjustments as needed" but *censored* happens. These codes are written for a good reason and should be followed. There isn't much that will kill a boiler but firing without water is a sure death warrant for any boiler.

 
lzaharis
Member
Posts: 2366
Joined: Sun. Mar. 25, 2007 8:41 pm
Location: Ithaca, New York
Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
Hand Fed Coal Boiler: former switzer CWW100-sold
Coal Size/Type: rice
Other Heating: kerosene for dual fuel Keystoker/unused

Post by lzaharis » Sun. Jan. 28, 2018 11:26 pm

In my case I do not have the fill valve open as I have a B+G steel compression tank and I have had no problems with my system which is protected by a McDonnel & Miller Guard Dog RB-122-E low water cut off.

If I left the fill valve open the system would become water logged and I would have no heat.

It all comes down to how you maintain your system and what type of system you have. you can never go wrong with a low water cut off in a hydronic system as long as your have it wired as the first control and line of defense for your boiler.
I have to remove the lwco in 3 years to clean the sensor tab that is in direct contact with the water in the steam chest and that is all I have to do to take care of it and I know its working because the green indicator LED is illuminated indicating it is working properly.

If you have a low water cut off as the first control in the system there is no reason you could not shut off the water fill valve in my opinion.

 
User avatar
Freddy
Member
Posts: 7293
Joined: Fri. Apr. 11, 2008 2:54 pm
Location: Orrington, Maine
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Coal Size/Type: Pea size, Superior, deep mined

Post by Freddy » Mon. Jan. 29, 2018 6:07 am

I don't leave mine open or closed. I leave it just barely open a crack. I have Entran in floor radiant heat. It has been recalled and will most surely crack and leak at some point. I don't want to leave the boiler without water, but I also don't want a major flood. If it leaks I'd like to think I will notice a big ol' puddle on the basement floor.... rather than a major flood.

Low water cut off and backflow preventers are not only common sense, they are the law here in Maine.

From my experience, pressure reducers usually fail low, not high....but anything can and does happen!

 
User avatar
nepacoal
Member
Posts: 1696
Joined: Wed. Nov. 21, 2012 7:49 am
Location: Coal Country
Stoker Coal Boiler: Keystoker KAA-4 / "Kelly" and an EFM 520 at my in-laws
Hand Fed Coal Boiler: Harman SF-260 - retired
Coal Size/Type: Buck

Post by nepacoal » Mon. Jan. 29, 2018 6:32 am

Mine is open. I have a 25 gal steel expansion tank and have only had to drain it once in 7 years. I added a "drain o tank" to it this fall to make it quick and easy to drain 7 years from now if needed. It simply part of the normal maintenance with steel tanks.

 
User avatar
Sting
Member
Posts: 2983
Joined: Mon. Feb. 25, 2008 4:24 pm
Location: Lower Fox Valley = Wisconsin
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG

Post by Sting » Sat. Feb. 10, 2018 6:03 pm

McGiever wrote:
Sat. Jan. 27, 2018 10:27 am
:idea: Our beloved member *Sting* has discussed or mentioned this subject in prior discussions. :idea:
I am sorry senator - But I have no recollection of that event :D

Post Reply

Return to “Stoker Coal Boilers Using Anthracite (Hydronic & Steam)”