Trouble filling hydronic system to second floor

p_finder_stlouis

Hello experts!

This is my second heating season in my 1931 bungalow, and I'm struggling to get my system filled and up to pressure after installing a radiator.

I completely drained the system by opening the bleed valves on my second floor radiators and opened the boiler drain valve.

After getting the radiator installed where an old one had been removed years ago, I went to re-fill the system. I have a Weil-McClain HE-4 boiler with a manual feeder valve and no back flow preventer. It has a circulating pump and this equipment is located in the basement.

At first, not knowing what I was doing, I attempted to fill the system with ALL of the radiator bleed valves open. My thought was that air wouldn't be trapped this way and I would close them when the radiators became filled. This sorta worked on the ground floor but at some point shortly after the ground floor radiators were filled the sound of water flowing into the system stopped. I was around 7 or 8psi. I wasn't sure if the sound of water flowing through the filler valve and piping was indicative of the system filling, or if, by the sound of water stopping, it meant that the system had for some reason stopped filling.

I waited on the second floor for the radiators to fill with water. It never came.

I turned on the system and determined the ground floor was flowing and my new radiator instal worked! Frustrated by not being able to properly pressurize the system, I decided to drain and start over, this time keeping the bleed valves closed. My thought was that if I bleed the radiators one at a time, I can build pressure in the system needed to get the water to the second floor.

So I started filling the system and bleeding the radiators in order of elevation. This was working, but I still didn't see my pressure go above 8psi. While filling the ground floor radiators and bleeding them one at a time, the sound of water flowing into the system would stop occasionally, then I would bleed a radiator and the water flow sound would continue. Stumped by this water flow sound stopping and continuing, I decided maybe I needed to bleed the boiler too, so I opened the emergency pressure release valve on the boiler for a few seconds. The sound of water flowing into the system would resume until, presumably, the boiler had refilled with water and the flow sound would stop.

I think that sums up where I'm at. I can't seem to pressurize my system by adding water. It SEEMS like the water stops flowing into the system for a reason I can't explain. I'm sure the city water pressure is normal. There are no leaks either. Why does the sound of flowing water into the system neutralize? I'd really like to do this myself if possible, I feel like I'm so close. Please help!

Phil in St. Louis

Mark Eatherton

1/2 PSI per foot of vertical system elevation above boiler, plus 5 PSI. Bottom fill, top vent (which you are doing). Adjust the pressure reducing valve to meet your elevation needs, typically 12 PSI for residential. May have a plugged strainer on the Pressure reducing valve.

Take pictures.

ME

p_finder_stlouis

Hi Mark, Thanks for the reply.

I haven't been able to locate a pressure reducing valve. Can it be located inside the boiler housing?

My setup appears to be pretty primitive, where the water line from the city supply comes to the boiler area, an inline valve to manually allow water flow to the unit...that line goes down and attaches to the expansion tank and then that attaches to the line that is just down-flow from the circulating pump.

Paul48

Have a plumber install an auto-fill regulator/backflow preventer. Set the system pressure at 15 psi, and bleed the radiators.

p_finder_stlouis

Paul48 said:

Have a plumber install an auto-fill regulator/backflow preventer. Set the system pressure at 15 psi, and bleed the radiators.

Hey thanks for the reply.

I agree, I'd like to have those installed. I am still stumped as to why I can't fill the system in the current configuration. It was full before and fully operational. What's causing the problem now though, prohibiting me of filling the system?

p_finder_stlouis

OK, I've been thinking about this auto-fill valve that I don't seem to have. I started to look at my expansion tank.


It's a "Fill-Trol" model 110. I looked this up and it says it eliminates the need for a separate, automatic fill valve. Factory pre-charged to 12psig.

Is it possible that this tank is no longer functioning correctly and prohibiting my ability to get past 8psi?

jumper

p_finder_stlouis said:

OK, I've been thinking about this auto-fill valve that I don't seem to have. I started to look at my expansion tank.


It's a "Fill-Trol" model 110. I looked this up and it says it eliminates the need for a separate, automatic fill valve. Factory pre-charged to 12psig.

Is it possible that this tank is no longer functioning correctly and prohibiting my ability to get past 8psi?

aha?

unclejohn

The tank is the problem. It has lost pressure and wont fill above 8#. You can try adding air with a bicycle pump and that may work get it to 12 #.

unclejohn

You could also get a washing machine hose and fill the system by the drain fitting until you get the tank pressurized or better yet replaced and do add that backflow. Also even better a combo backflow and reducing valve and a standard extrol tank.

p_finder_stlouis

unclejohn said:

You could also get a washing machine hose and fill the system by the drain fitting until you get the tank pressurized or better yet replaced and do add that backflow. Also even better a combo backflow and reducing valve and a standard extrol tank.

Thank you UncleJohn!

I put a bike pump on it with a gauge I trust accurately and sure enough, there was very little pressure in the tank. I pumped it up to around 12psi. Going to put some things back together and try and fill her up.

I'll work on getting the parts mentioned for a future upgrade.

Thanks!!
Phil

leonz

Be sure to check by your water meter for a pressure reducing valve AND do not touch it.

You might want to consider using a 15 gallon steel expansion tank with an airtrol valve instead of a new bladder tank as the air charge never leaves the tank.

EBEBRATT-Ed

?????? not getting this. Drain the boiler water out of the system. When it is drained check the expansion tank pressure. It should be 12-15 psi. If not blow it up with a bicycle pump. If it doesn't hold pressure you would then have to replace the tank.

Hook up city water to your drain hose and fill the system with water via the drain valve. Use a female x female hose adapter or washing machine hose to do this. Bring the system up to 20 psi and bleed the radiators. Shut the water off while you are bleeding. continue filling and bleeding until done

When you are done bleeding drain some water to get the pressure down to 12-15 psi.

Have a plumber install a prv and find out why the system won't fill from the city water line

Paul48

It takes .434 psi to raise water 1 foot. So, if it's 20 feet from the point you feed your system to your highest point of radiation....20x.434=8.68 psi. Throw in a few pounds as a safety factor and call it 12 psi. You have to maintain that pressure while you're bleeding the radiators. An auto-fill regulator allows you to do that. Your expansion tank will not do that, and has nothing to do with your inability to get the air out of your system.

Jim Hankinson

His Fill-trol should do that. It's a combo expansion tank and PRV which is supposed to maintain system pressure based on the air pressure in the tank so 12 psi in the tank should give 12 psi in the heating system. The disadvantage of this system is that there's no fast fill.

p_finder_stlouis

Jim Hankinson said:

His Fill-trol should do that. It's a combo expansion tank and PRV which is supposed to maintain system pressure based on the air pressure in the tank so 12 psi in the tank should give 12 psi in the heating system. The disadvantage of this system is that there's no fast fill.

Indeed!

I wanted to post an update... thanks to everyone's help and some critical thinking and beard scratching I was able to fix my issue as a complete novice. It seems my fill-trol tank was low on air, so I pumped it up to around 12-14 psi. I was able to fill the system back up and once I hit about 14/15psi, the Fill-trol's companion PRV shut the flow of water off. So the valve still functions, just at a higher pressure, which is exactly what I needed. Also, before anyone tells me thats too high of pressure, I made sure my final cold pressure was right at 12psi.

Everything is back to functional, and next season I'll close the system down and do a few upgrades including a back flow preventer.

Thanks for your help everyone!

Phil

Mark Eatherton

Thanks for checking back in. We appreciate it.

ME