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Effar 12-26-2011 09:57 AM

Reducing water pressure of the heating system

I have a Dunkirk XEB-6 furnace. First, the pressure was a little bit high around 25 psi. The manual said that the pressure should between 12 and 20 psi. I thought that the relief valve is not working. so i went ahead and tested it by lifting the lever and releasing some water. after that the water did not stop dripping from the relief valve. I realized that I did not turn the system off before messing with the relief valve. System turned off and cooled off and the water still dripping from the relief valve and the pressure still high (around 27psi). Next i used the "reducing valve" to reduce pressure. after the system was turned on, the pressure reached 37 psi (too dangerous). Using the reducing valve didn't help reducing the pressure. I turned the heating system off and we are freezing now

By the way, i have only one gauge on the top of the furnace. No gauge next to the reducing valve.

Advice please

Thank you

TarheelTerp 12-26-2011 10:10 AM


Originally Posted by Effar (Post 803411)
I have a Dunkirk XEB-6 (BOILER) furnace.
Advice please Thank you

At the bottom of this page you'll find a link to installation instructions for your equipment. Get the .pdf, study it, compare that information (in particular the piping and controls) to what you have.

Once you are absolutely certain that the installation is correct...
then you can delve into the troubleshooting and possible replacement of parts or components. But not before.

Also... check your yellow pages for "boiler" and "controls".
If you don't already have a local pro to backstop you... find one.


harleyrider 12-26-2011 11:08 AM

scalding hot water under pressure.............sorry, not a diy safe your life and your a pro.

Effar 12-26-2011 11:11 AM

Reducing water pressure of the heating system
Thank you for your fast reply.
I already went through those Dunkirk PDF files before i posted my first message but they did not help. The heating system was working just fine for years. on previous years the relief valve releases some water from time to time to reduce the water pressure. So this year i did not see any water coming out from the pipe connected to the relief valve and the pressure was a little bit high about 25psi. therefore i went checking the relief valve to check if it working and problems started to get complicated from there. I wish i left the system alone.

I tried to attached some pics but they are large file.

Thank you


Effar 12-26-2011 11:14 AM

I think you are. I should call a pro.


how 12-26-2011 01:30 PM

You've had a long time problem with this boiler. Adjusting the pressure reducing valve on a boiler is best left up to a pro but we can probaby try to get your boiler back working through this holliday.

What exact steps did you take to adjust the pressure reducing valve and can you exactly reverse them?
Do this with the water feed to the boiler and the power turned off.
Turn the water back on when your finished and let us know what the pressure reads but leave the power off.

Effar 12-26-2011 02:38 PM

Here is the reducing pressure valve i have ( it is a dual unit valve.
I understand now why the pressure increased when i adjusted the reducing valve. I was adding water to the system instead of reducing the pressure because i left the lever instead of turning the adjusting screw counterclockwise. so to reverse what i have done i think i should take water out of the system. How i would do that?

Thank you

how 12-26-2011 03:13 PM

If all you did was lift the lever on the pressure reducing valve then you did not adjust it, you temporaily bypassed it. So you gave the boiler a shot of house/street pressure. The relief valve would have opened and drained off that excess pressure.
What does the guage measure in PSI right now? Is the gate valve that supplys the boiler with water open right now?
Probably the only thing different about your boiler today over last week is that your relief valve isn't reseating itself.

Lift up the lever on the relief valve so that it momentarily vents and then let go of it to let the lever spring back closed again. This should happen with a bit of a snap. If the continuous relief valve venting was caused by debris trapped over the seat of the valve then this action may clear it. If the valve seat is scored or the relief valve is venting at too low a real pressure or if your boiler pressure is actually higher than the guage indicates then this will not correct anything.
Let us know what the pressures reads on that guage but if that relief valve continues to dribble, that should not stop you from heating your house until after the holidays are over. Your boiler does sounds like it needs servicing but it has been causing that relief valve to vent occasionally for years so I don't see the need for you to be going cold or paying premium holiday plumbing rates.

Effar 12-26-2011 04:36 PM

After I turned the system off and I drained some water off using the relief valve, the pressure in the gauge went down from 35 to 25 psi. Now I just turned the heat on. I will let you know what will happen. Thank you for you support.

Effar 12-26-2011 05:08 PM

So after i turned the heating on, the pressure gradually increases from 25 psi to 40 psi. I turned the heating off when it reach 40 for safety. I was afraid it will blow up or something after 40 psi. The relief is supposed to operate and get rid of some water when the pressure reaches 30 psi. But the relief valve seems to get rid of only some few drop of water and stopped leaking as the pressure increases.
By the way, the relief valve was not at all leaking before turning the heat.

Any thoughts?

Thank you

TarheelTerp 12-26-2011 05:27 PM


Originally Posted by Effar (Post 803748)
the pressure gradually increases from 25 psi to 40 psi.
I turned the heating off when it reach 40 for safety.
I was afraid it will blow up or something after 40 psi.

What is the "normal" operating pressure supposed to be?
And what number is on the relief valve installed now?

If this were my boiler it would have a few new parts before dinner tomorrow:
a pressure gauge (or two), a relief valve, and an aquastat


how 12-26-2011 05:57 PM

It's unusual for a pressure relief valve not to release at 30+ (especially one that has been releasing on a regular basis). The real water pressure in your boiler compared to what the guage is saying is in question.
Either you need to pick up a pressure guage ( I've seen them sold at box hardware stores to folks that want to measure their house water pressure). The guage shouldn't read over 150PSI or it will be a pain to read.. It should have a female 3/4" hose connection that would work on a garden hose or the boiler drain valve. You can screw that onto your boiler drain valve and then open the valve to get another check on the water pressure.

If that's more than your comfortable with then it's pro time.

Effar 12-26-2011 06:00 PM

The normal operation pressure between 10 and 15 psi.
the pressure number on the installed relief valve is 30 psi.
I am thinking that either the relief valve or the gauge is faulty !


Effar 12-26-2011 06:07 PM

I forgot to mention that when I bleed the radiators yesterday. the radiator of the bathroom on the second floor released some air but no water come out after the air is released. If the heating system is high in pressure, it should pushs the water out as i open the valve of the radiator after all the air is escaped.

There is something fishy in my heating system.


biggles 12-26-2011 06:38 PM

that regulator is set for 12lbs and that's with a cold boiler or just drained down till it stops feeding at 12psi.don't lft the maunal lever up see that nut that is the factory setting of the tag info saying drain the boiler pressure off and let it feed to 12psi,,,,then run you boiler from the stat when the house is comfortable and the stat shuts the boiler off you should be just above 20psi but not near 30psi....put a bucket under the relief let it drip blow it off fter the boiler cycles off.crap in the seat.keep in mind your city pressure is way over what the boiler needs 50-75 even100psi on the cold water into the house..that's why they install 12psi regulators on all cold water inlets on boilers..if you adjusted the stem/nut on that regulator when you see 12psi on the guage loosen then nut and turn the stem CCWlooking down on it you'll hear the water stop feeding...turn it CW your pushing the tension spring down on the bellows and increasing the 12psi higher...and you'll hear water feeding in and the guage rise.8 psi to 10 psi from a cold boiler start to satisfying a space is plenty NOTE: do all the pressure adjustment with the boiler off to check for that 12psi cold if possible..

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