Prv thrush valve recommendation

photokynetics

I have an aqua balance water heating system that the thrush valve keeps hanging up and I believe needs repaired or replaced, what is a recommended regulator valve? Maybe there is one better than this one that won't wear out so fast or need so much attention?

EdTheHeaterMan

From what little I can see in that photo, you need to get a professional to review that work. Especially the relief valve configuration. Also, there is no safe discharge or safety tube attached to your back-flow preventer

Other than that, I have no idea what that arrow is pointing to. But I never installed or serviced that brand of equipment.

Edit: what can happen if your relief valve does not work because it is installed backwards

https://makeagif.com/gif/mythbusters-water-heater-explosion-yInJnq

photokynetics

This was installed by the previous owner and has already passed usable inspections, I'm just trying to get it winter Worthy, that arrow was pointing out a little shut off valve

EdTheHeaterMan

Can you provide a photo of the entire system? You may not have a problem, but I can't tell what you have.

It's kind of like asking what spark plug this car should use?

Spoiler Warning

Trick Question… it is actually a truck

photokynetics

Here are photos of the whole system, it was installed by the previous owner, it looses pressure in the system over time, short time, like a few hours, but I've looked for leaks from the top to the bottom and can see no leaks, not even a drop!

Thank you for your help!

mattmia2

Is that an air compressor tank being used as a buffer tank? or maybe a well tank

Jamie Hall

When you say it loses pressure — what exactly does that mean? What is the pressure in the system when it is hot, and what does the pressure drop to when it is off?

Does the pressure come back up when the system heats up again?

To determine whether or not you have a leak — regardless of whether you can see it or not — somewhere in that system there must be a valve you can close to completely turn off the water to it. Close it, and then see what the pressure does over a heating cycle.

I'm quite suspicious of the expansion tank either failed or lost its charge — or just simply undersized.

Kindly report back…

photokynetics

That is and air compressor tank that he put in there he said it was just for a reserve, I don't know what he's thinking was, there is about there's 2000 where I can pressurize the system up to 19 or 20 psi then close those valves and the pressure eventually drops down to six or seven PSI and that's when the the boilers will shut off, the pressure will drop from 20 down to six or seven sometimes as fast as within it an hour, and when it's heating up and running through the heating cycle pressure never gets above 20 it usually likes 18 when it's not running and when it heats up it'll go up to 20.

EdTheHeaterMan

What are you using for heating the space, the rooms? Radiators? Radiant floor? Baseboard heaters?

The leak may not be in the boiler room, the Leak may be anywhere in the system.

mattmia2

Did you check the precharge of that home depot dhw expansion tank?

EdTheHeaterMan

The previous homeowner did not do you any favors. The wrong piping is used for the supply and return of the closed system. it looks like CPVC on the supply and PVC on the return. That pipe does not have the necessary Oxygen Barrier to prevent the non ferrous metal parts (like the buffer tank, steel pipe, iron fittings and the circulator pump) from rusting away.

You have a leak somewhere and you should get the Home Inspector that told you that system is operational to see if his insurance covers the cost of making this system right. Did you have a boiler expert inspect that job before you purchased that home? You may have a major repipe on your hands.

Jamie Hall

Trying to be kind here, but… I think the reason we are having a little difficulty in trying to figure out what might be going on is that, frankly, we've never seen anything cobbled together in quite that way. Or to be more blunt… it's a mess.

However, messes sometimes work. Sometimes. You didn't answer my question, though. If you close any water feed to the system from your domestic water supply, what happens to the pressure?

hot_rod

The leak could be in the wall or tubing in a slab?

7 psi X .433= 3.03 feet, that is the location of a potential if it never drops below 7 psi.

photokynetics

Thank you for your patience! With the water feed valves shut off the pressure in the system will eventually drop down to 7 to 5 lb I don't recall if it ever goes to zero, cuz sometimes it will do that in just 2 hours or so of closing the feed valves, The hot water goes through aluminum type radiators that are in the walls, none of the plumbing goes into the cement floor this is an afterthought system that was installed when the house was 30 years old, I have walked this entire system and I can't find any water of any kind leaking, I had a professional come and help me fix it shortly after I moved in and he went up into the Attic where part of the heating Lines go to but he found no leaks either. He determined the problem to be air in the system which he bled out and then everything worked fine for a couple of weeks and then started losing pressure again. He looked at the expansion tank and determine that it was okay but I don't know if it is, maybe it's lost its pressure. I get the suspicious feeling that there is multiple problems here. Part of the problem was the preventer valve was locking up and not letting the system pressurize when I open the valves, so I changed it, and now it will pressurize manually just fine, but the regulator seems to need replaced or repaired if it can be repaired, the pressure went back down below 10 lb and when I opened up the pressure regulator it pressurizes the system immediately. I'm afraid he plumbed this with the wrong plumbing but it was inspected when it was installed by a local inspector so I had no questions or any doubts about how it's installed or design especially since I never even seen one like this.

Jamie Hall

"since I never even seen one like this"

Cheer up. Neither have we…

The pressure regulating may need replacement — or maybe just adjustment. My first thought to check, however, is that expansion tank.

A bit easier said that none, as it must be drained to do it properly. I can't really see in any of the photos how it connects to the system (it almost looks as though it is connected to the pressure relief valve on the big tank, but I sincerely hope not…). Further, its water inlet is at the top. One way or another you have to get it empty of water… then check the air pressure at the air valve. That should be around 12 psi.

EdTheHeaterMan

I still can't imagine how the system is connected to the boiler, If this is the SpaceHeating only model then where are these pipes?

The pipes connected to #1 and #5 are hard to see in your photos.

Can you take a picture like this?

Maybe a little further back so we can see the pipe connections and where they go from there.

photokynetics

Here a few photos hopefully you can make sense, the black pipe on the far right connects to the circulation pump and the bottom of the expansion tank or air compressor tank, many has the other pipe on the left side the red side listed as domestic hot water, and I remember he said this thing can be used to heat water for the water heater as well when you close a couple of valves but right now it mainly heats water for the boiler system to warm the house. Then the expansion tank connects to the upper side of this air compressor and it looks like there's two valves that I can close so the whole system don't need to be drained just everything out of the first 6 in of that air compressor tank.

Jamie Hall

I hope I'm not seeing what I think I'm seeing in that first picture just above.

What I THINK I'm seeing is a nipple coming out of the big tank to the leg of a T. Then one side of the T goes to the pressure relief valve, and the other to the expansion tank.

I see no valve between the expansion tank and the big tank. I can see how to get the expansion tank off the piping — but it's full of water as it may well be, it's going to be really heavy, so when you go to unthread it support it somehow.

What I really don't like is the use of plastic pipe off the pressure relief valve to who knows where.

Frankly, and not to put too fine a point on it, if I were your building inspector I'd fail the whole system. The more I see the less I like.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1809944#Comment_1809944

There is a tee connected to the umm…buffer tank, the side of the tee goes in to the tank and the run connects to the expansion tank and the relief valve.

Can you see if there is water coming out of the pipe from the relief valve when the system heats?

Unless the house is more than 2 stories the cold fill pressure should be fine at about 12 psig.

If you pressurize the system with everything cold and wait with the system cold does it lose pressure?

photokynetics

I can get water out of the relief valve when the system is heating up.

I will try filling the system cold and see if it looses pressure cold.

mattmia2

There is some issue with the expansion tank if you get water from the relief valve as it is heating. Either the precharge is wrong(if that dhw tank hasn't been adjusted down to about 12 psig that in itself could do it), it has lost its precharge, or it is too small for the volume of the system.

photokynetics

I get water out of the valve when it's heating up, but only if I open the valve. Sorry for any confusion!