Burner pressure keeps rising!

cicero38

I had to divert a copper pipe in my kitchen's baseboard heating zone, so I turned off the electricity to my boiler, shut off the zone in question, and finally drained any water in the zone. After I made the changes (soldering a diverted line), I tried to flush out any air in the system, and turned all the valves as I had found them. The problem is, the PSI seems to be going up and up, without any sign of ending!!! Before shutting of the zone, the boiler was reading 12PSI, now it reads about 21 PSI (and this is after I've drained the diverted zone a few times to relieve the pressure).
Sorry, first time doing this kind of repair - so I don't really know the correct terminology. I've included a photo of my system with the valves I had touched circled in red.
Can anyone please help? I think my boiler's pressure is way above normal, and I'm afraid something will get damaged soon.

JUGHNE

Somewhere near the boiler is a cold water feed valve. If you shut it off, the pressure should stop rising. Look for a cold water line, this is city line pressure, would connect to your bath & kitchen cold etc. Find that and close then post picture of that valve. Your boiler relief valve should open at 30PSI, not a major issue if you have a floor drain handy. Let us know......

cicero38

Sorry I should have mentioned that I use well water. Would that make any difference?

JUGHNE

No, your house would/should be plumbed just as a city water house. If you can't find the boiler fill valve, you could shut off the main water from the well/storage tank.

cicero38

Ok, after looking online for a 'boiler fill valve' (!), I'm pretty sure I don't have one installed. Is this possible? I could definitely shut off my main water valve - would a picture of this help? Thanks a lot JUGHNE for the help so far.

JUGHNE

Bottom center valve that feeds the gray air tank hanging on the pipe. That could be the water feeder. Shut that off and follow the copper pipe back to would be a fill valve regulator.

cicero38

If I understood you correctly, I've taken two angled of the connection (capped by the green plastic bit). Is this what you meant? I can't seem to find a valve here (or am I looking at the wrong place?).

JUGHNE

Look at the air tank, the small tee on the top, there is a green cylinder device, then back to a back flow preventer, straight thru that it says "inlet"......follow that inlet pipe until you find a water valve and shut it off. I assume you have the boiler off.

cicero38

Ok, so I found the next valve from where you had indicated the "inlet" label. I shut that off (look at photo with my finger on the valve). To clarify, this has always been open, but per your instructions I had turned it to off. The second photo shows that this valve leads to another valve (open). The third photo shows that there are 2 additional stop valves from where the valve I'm touching leads.

JUGHNE

That valve should stop the well water from going into the boiler, did the pressure stop rising?? And Shut the burner off!
Awaiting your reply with baited breath.....what the hell does that mean anyway.

cicero38

Yes! Thanks for reminding me - I shut the power off to the burner. Also, it's been about 8-10 minutes, and the pressure has not risen (nice!). When would I turn this valve back to on? Are there more steps to stabilize the pressure?

EBEBRATT-Ed

I believe with @JUGHNE's help you have shut off the correct valve.

Most likely what happened is that your pressure reducing valve is stuck or dirty (the one with the green plastic cap) . This valve is supposed to take well water at 40 psi (or whatever is on your water system) and feed it into your boiler as needed at a reduced pressure of 12-15 psi.

Most likely the green valve has stuck or failed because it has never been used in a long time (because your system is tight and never needed water) and is now stuck open.

cicero38

ah-ha! is there any way to clean or 'reset' this valve? Would I need to change it altogether? If so, what's the technical name for this component?

STEVEusaPA

You have to get the air out. How did you try to purge the zone?
You would need to open the water feed, hook a hose up to the drain on the zone, close the valve below the drain, manually open that zones's zone valve, open the drain to the hose. When you're opening the drain you have to watch the gauge and not let the pressure drop by simultaneously filling, draining & maintaining pressure.
It's actually way easier to show and do it than to explain it.

JUGHNE

OK, you need to know more about your plumbing. The valve you shut off (red handle ball valve) is the cold supply for the boiler. Just above that is a tee, go right and the 3/4" line connects into what looks to be 1" tee coming down thru the ceiling.
Follow from that tee to the right and those valves feed cold water to somewhere in your house....(1st or 2nd floor etc).

Back to your boiler feed valve, up to that tee, go left that feeds cold water into the top of your domestic hot water mixing valve and also goes down into the insert coil stuck into the boiler. The hot domestic water comes out of that coil and into the bottom of that mixing valve with the green knob. (not to be confused with the boiler fill valve with the green cylinder.)
The pipe coming out of the side of the green knob valve is the hot water for your house..shower, sinks etc.
All of this is called domestic water supply and does not go directly thru the boiler.

Now when you drained that zone and tried to fill it again your fill valve opened to put water back into the boiler and should have brought the pressure up to about 12 PSI. However it has not had to function for a long time and your refill woke it up and it over acted.

Now keeping the boiler fill valve off, you could drain some water as you did before and drop the pressure to 12 Psi.
You could then run the boiler with the water supply shut off. Not recommended to leave this without water on. You could warm up the house overnight. You need to monitor the pressure to assure you have no leaks.....you did just change some piping.

I believe that is a Taco fill valve. It is to maintain your 12 PSI and add water if needed. Google the model number, you may find a parts/repair sheet. Figure out how it works, there is probably an inlet screen in the bottom that may need cleaning. Before opening or removing you need to isolate it from the system....
supply water off, of course......close all the valves to the zones.....keep the electric zone valves unpowered. Then drain some water out of the boiler to drop the pressure. You are trying to keep the water in the piping/radiators that is above the boiler.

JUGHNE

And I must add that you had a very thoughtful plumber to install that many valves for your convenience.....domestic water and boiler zones!!

cicero38

Thanks so much everyone, this has been both a relief (!!!) and an education. @STEVEusaPA, I think I know what you mean - I may have purged the air out incorrectly... I'll try to re-purge the zone tomorrow when there's daylight (I think my neighbors are becoming suspicious as to my flashlight activities at night!). @JUGHNE, you've been a huge help! You've written a lot in your last full comment, so I'll be studying that tonight! Indeed, I bit off more than I could chew - thankfully you guys helped to save the day! You rock!

cicero38

after thinking through the final solution, would it be safe to use hot water tonight and tomorrow morning? Wouldn't there be a problem in that there is no new cold water coming in?

JUGHNE

The only water supply you should have shut off is the house water supply to the "stuck" pressure fill/regulator valve that adds water to the boiler.
All other valves should be open.

If you follow the cold supply to the left that next valve should be open as it is supplying water to the domestic hot water heating coil. Do you have any sort of storage tank for household hot water??

For the boiler insert coil to get heat, the boiler will have to fire.
You need to keep 12 PSI in the boiler as it fires. Tap the gauge to make sure the needle moves, (yes, just like the movies).
It can be 12 when cold and as it heats the pressure may rise to 15 or so as the water expands.

cicero38

Thanks JUGHNE, that's what I had guessed regarding the hot water for the bathrooms (but I don't have any experience on this to trust!). I tried turning the valve back on to allow cold water into the boiler to see what would happen (the one that you told me to turn off), and I noticed that the pressure was no longer rising as had been the case last night. I turned it back off just in case - but is it possible that my Taco Fill Valve somehow got 'unstuck', meaning it is now working as it should?

JUGHNE

You may have exercised it enough to function as it should.
You should check the screen that is on the bottom. If you download the install/troubleshoot/service instructions, you would see what is being talked about. They have a limited life span. The more you exercise it the better it might operate (or not).

Does your boiler run in the summer to heat your domestic hot water? Or do you have maybe an electric water heater downstream of the boiler?

cicero38

Yeah, I wanted to find maintenance directions for the Taco 3350-T2, but I'm having trouble finding one online, as it's been deprecated by the T3 version... perhaps I'll update it soon.
And yes, my boiler runs year round as we don't have an electric water heater - why do you ask?

cjay

I have same problem. Boiler is cold. as soon as I am adding cold water to boiler, pressure keep on rising. But if I switch off the valve which moves cold water from boiler to water heater, pressure stop rising..... my question: can I shut that valve off positon permanentlt and run the boiler? If not, how to stop the pressure keep rising.......

STEVEusaPA

You should start a new post. Could be a number of issues. If you shut off the valve, and you have a small barely noticeable leak somewhere, and no low water cut off, you're boiler could run out of water, dry fire and/or get slammed with cold water in a piping hot boiler and (if you're lucky) crack and fail. If you're unlucky...something very worse.
You have to get to the root of the problem and answer the following questions:
-Why do I need to add lots of water?
-Is there a leak?
-Is the water feed partially stuck open?
-Is the relief valve dripping, dropping pressure, feed adds water, air causes pressure rise, relief valve blows, pressure drops, feed adds water...over and over again?
-Expansion tank working properly, or in the case of a steel tank, not water logged?

I wouldn't shut off the valve until a professional confirms all the components are working properly, the system is purged of all air, AND you have a low water cut-off.

cjay

I have changed PRV in boiler, expansion tank is good. Aquastat has a low water cut off switch on, so may be its ok, not sure...... I have seen pressure keep on building up if I open that valve. I didn't see any physical leak..... I got the heat upstairs by doing so (baseboard heater) but nt getting the hot water upstairs...I am worried for worst case scenarion of course, just its so cold and run the boiler to heat up the home....so:
1. is that problematic if I have switch off the cold water valve from the boiler to the heater?
2. I am not getting hot water upstairs (getting baseboard heat though which runs in hot water).... is that the problem?

HVACNUT

Are you not getting hot water upstairs or no water at all from the faucets? If no water, then you have the valve off for the domestic hot. The valve you point to with the red arrow in your last pic.

cjay

I am not getting hot water in upstair..... I am getting cold water everywhere...... looks like as soon as my boiler is connected to hot water heater, pressure increasing. don't know why?????

STEVEusaPA

cjay said:

I am not getting hot water in upstair..... I am getting cold water everywhere...... looks like as soon as my boiler is connected to hot water heater, pressure increasing. don't know why?????

I told you why