My water pressure is too high

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d bradley

New Member
Dec 19, 2017
1
maine
I have a Titan T 101 wood boiler integrated into my oil burner. Whenever I give it any kind of serious fire (more than two or three pieces of wood) it over pressurizes to 40 psi and starts releasing water into the wood box. Temperature runs consistently between 180 & 190 degrees and the auto damper seems to work fine. If I turn on the second floor heat zone the pressure drops to under thirty psi but only until that zone heats up to temperature and then the pressure problem starts all over again. I have only lived in the home four years and have always had this problem. I have had my oil furnace serviced including installing a new low pressure cut off switch and replaced the high pressure relief valve on the wood boiler. Chimney and wood boiler freshly cleaned two weeks ago and I dismantle and clean the wood boiler, accumulator and pipe every two weeks. (Not that any of that matters) Does it need more cold water somehow? Any help would be greatly appreciated.
 
No - more water will only make the pressure increase more.

I suspect your fresh feed valve is malfunctioning and letting too much make up water into the system. That could be caused by a bit of dirt in its guts - or there could be something broken in it that would require replacing it. Without pictures we're a bit in the dark here - but if it were my system, I would turn off the valve that supplies the fresh feed pressure regulator. Then, there should be a little manually operated lever flipper thingie on top of the regulator - it could be flipped open & closed a couple of times to see if that would dislodge any dirt. But make sure the water that would be released out the bottom of it gets directed to somewhere it won't hurt anything. Make sure the flipper thingie gets closed again Then I would drain enough water out of the system to get pressure down to a more acceptable one. Like maybe 12 psi. Let things stabilize at that. Then open the valve to the fresh water feed back up again and see what that does to your pressure. If it starts going up again, like to 20, then you still have a problem with the regulator and it might need replaced. Or taken apart and the guts cleaned out. If you can isolate it on each side, you should be able to to that while leaving the body in place. If taking apart & cleaning doesn't fix it, or you find something broken inside, you also might be able to fix that while leaving the body in place by buying a new regulator the exact same as the old one, and swapping the new guts into the old body. Also these are usually adjustable - but not to 40 psi adjustable. So I don't think trying to adjust it would fix your problem. But you might have to adjust it, after you do any servicing. I think they are usually factory set to around 12 though.

Another thing that can make pressures go wonky is a bad or water logged expansion tank - but that doesn't usually make pressures go that high.

Any boiler servicing tech should be able to fix this, these are standard things for most any boiler system no matter the heat source. Also I might consider diverting that pipe that sends water into the wood box, into a bucket or drain. I can understand why it was done that way but IMO the potential for messing up your firebox via a malfunction(such as this) outweighs potential good it would serve as long as everything else in the system is working as it should.
 
Just thought of something else. If it has a DHW coil in it, that might also have sprung a leak internally so it is leaking domestic (higher pressure) water into the boiler. I would first suspect a cruddy regulator - to troubleshoot, isolate one or the other then drain the pressure down. Then un-isolate it & see what happens to pressure. But 4 years is a long time to live with this problem, also thinking uccky boiler water would have creeped into your DHW by now if it was a leaky coil, which should have been noticeable.
 
Agree ! Start with Isolating your fresh make-up water. Drain pressure to 12-15 psi and watch during a full cycle of heating. Costs to replace regulator will be about $35. which is the route I would take verse rebuilding. I run my system with the regulator isolated with small ball valves on both sides and only open it up to increase pressure or a need for significant make-up using the bail.
 
Not meaning to post so much without hearing back from the OP. But I was a little off in my first post. The lever flippy thingie I was talking about, won't let water out of the system. It will just let water in, if it's not being let in already. I was thinking of the lever flippie thingie, on a relief valve - those have an outlet on the bottom that will blow off, but also manually let water out by raising the lever. I have one of each on my fill line, one after the other. I also keep my fill valved off all the time unless I need to add more water. Don't know whether I would or not if I didn't have storage - always kept it open before I added storage.
 
The autofill valve has a rubber diaphram inside of it that gets old and cracks especially if you are using the fast fill function. I think there is rebuild kit but most folks just change them out.

Next thing to check is that your expansion tanks arent waterlogged. They also use a internal diaphram that gets old at some point and fails. When that happens the system pressure will go up anytime you heat the water as there is no room for expansion in the system.
 
I had a weird issue with over pressurizing with the water fill valve on my pellet/oil boiler retrofit.

Because of the boiler protection valve and check valves, the boilers become isolated from the distribution system when they cool down.

I put in an autofill line on either side of the protection valve for filling purposes, and the expansion tank is on the distribution side of the protection valve.

I turned off one of the autofill feed's isolation valves because I was concerned about flow bypass around protection valve.

With all autofill feeds closed, pellet boiler pressure got down pretty low when cold. With autofill turned on to only the boiler side of the protection valve, some amount of water would enter to maintain the 12 psi setpoint of the autofill valve. This cycle would continue until the pressure relief valve mysteriously blew.

In retrospect, perhaps the expansion tank should've been connected on the boiler side of the protection valve.
In retrospect, perhaps the pellet boiler was a big waste of money, but that's something else. :)

Now, I just keep both feeds open and accept a little bypass around the protection valve.

Anyways, could be something weird like that.
 
Something fishy there. The boiler should not drop pressure below the cold fill pressure. Unless you move it outside and temperature drops below what you filled with and at?

Also pressure should not increase, maybe 5-10 psi if expansion tank is installed and pressurized correctly.

Is the pressure gauge at the boiler? Most check valves are not tight sealing, what they call a bubble free seal, so the pressure should be about the same on both sides when no pumps are operating.
 
Something's fishy alright. :)
The low boiler pressure came back to the pressure of the distribution system when the boiler protection valve opened.
Spring check valves.

I didn't want to make this thread about me, just saying that it could be some weird valve lineup, or the like.
 
There are a couple pieces of information here. One of which has me baffled. I know nothing of the boiler in question. The first piece states that the pressure increases at higher temperatures and we all have similar ideas as to why. The second is that it releases water into the firebox. WHAT--- SAY THAT AGAIN! Am I missing something?
 
There are a couple pieces of information here. One of which has me baffled. I know nothing of the boiler in question. The first piece states that the pressure increases at higher temperatures and we all have similar ideas as to why. The second is that it releases water into the firebox. WHAT--- SAY THAT AGAIN! Am I missing something?

That's how that boiler was designed - the blow off port, gets plumbed with a piece of copper thru a hole in the firebox. Idea being, if it overheated it would put the fire out. My father has one of these. Like I said above - might sound like a good idea at first glance, but....

EDIT: It's a Kerr. Who also made the Jetstream at one time. The Titan is a decent conventional boiler, with tubes. But they need periodic tube cleaning which can be messy. Adding storage to it would improve it tremendously.
 
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My Burnham has a similar set up. It has a two safety reliefs, one is 30 psi unit plumbed to the floor and the other was a 27 psi unit (which is custom). I have not located a 27 psi relief off the shelf so its plumbed to the original port that runs through the jacket of the boiler and into the side of the firebox.