I'm trying to figure out whats going on with my boiler. It's oil fired 37 years old and all the parts were replaced back in 2005. The records I have. The house water pressure is 65 psi. I replaces some parts over past 12 years. The boiler used to read about 15 to 18 psi on the gauge on the boiler. Now it's reading 4 psi cold and 6 psi when running. Its three zones for base board heat with a forth for indirect hot water tank. Last year it was down at 10 psi. I drained the boiler down and just replaced the automatic air vet because it was leaking. The psi was the same before and after. The expansion tank sounds empty like it should. I was think this is the problem but not sure and what should the tank psi be set too. The check valve next to the expansion tank is not leaking any water nor is the main relief valve on the boiler. I know when I first moved in the boiler had 0 psi, no hot water or heat and I had a company come out and they removed the expansion tank and refilled it with air. I have been cleaning and giving a tune up ever year since.
15-18 psi is an acceptable pressure for cold water in a boiler. The water supply valve to the boiler can be manual or automatic. Since the pressure is decreasing, the supply valve can't be the problem since you state the supply pressure is 65 psi. Most likely there is a leak in the boiler water jacket or one of the 4 zones including the heat exchanger in the HW tank. If you have valves to isolate zones, you can operate on one zone and watch for a pressure drop unless the drop is so slow that it makes this approach impractical.
I can isolate each zone. I have ball valves for each zone feed and out.The supply valve on the boiler in red and Manuel bolt on top. I will try and see what I get. It was like that over the summer so I would think in the HW tank maybe. If the jacket is leaking how could I know or what can I look for? I figure if it is this, it can't be fixed and it's time fore a new boiler?
Isolate the 4 zones closing the feed and return valves. Pressurize boiler to 25 psi. If pressure doesn't hold, there is a water leak in boiler (water jacket or piping).
m,
If your boiler was leaking you would see water on the floor.
If your feed valve is working it would feed water back in as water leaked out. Since it isn't then it's either defective or you do not need water.
Your expansion tank should have at least 12 psi for its charge and should sound solid at the top and hollow at the bottom where the bladder is.
If your Indirect coil had a leak it would continually feed your boiler and your relief valve would activate at 30 psi.
It could be as simple as your gage not working.
If all your zones heat and if you have 2 stories and you have water in those zones, that would take more than 4 psi to fill those pipes. Another reason to check your gage.
No water at all leaking. And when I cleaned it I swung the door open and cleaned and inspected inside the boiler. no signs of water leaking in there either,
I did run the heat last week and I have a split 1.5 stores with no problems.
No heat on last night or hot water being used, I looked at the boiler and it read 0 psi. No water anywhere. The indirect called for heat and the boiler turned on and it went up and maintained 10 psi. So no idea what it could be. I do have a threaded psi gauge I can thread into the boiler drain and open it up and see what it reads. If it is the gauge on the boiler going.
The expansion tank, okay, yes is solid on top and empty on the bottom, but I did not check the psi on the tank yet.
Tank sounding correct only means there is some air in there but not necessarily the proper amt. You need to check your pressure. If you really have low pressure then feel the cold water line between the boiler and your feed valve. If it's cold then water is feeding in, if it's warm or room temp then it's not. Lift up the fast fill lever to see if it works, but not for long in case it is your gage, you don't want to add too much intil you know your right pressure.
The water feed line is cold feeding the boiler. I do not have a fill valve for the boiler. the supply comes in, goes through a backflow then a flow control valve, that's it. see pictures below. I still have to check psi on the tank and in the boiler. had no time this week. heats on and working fine. boilers at 5 psi on the gauge.
M,
You do not have a traditional feed valve on your system. You have a Filtrol system. It is a special valve attached to your expansion tank. If you take the tin foil off the top of the expansion tank you can see it. You change the pressure in your system by adding air to the tank which has to have the water removed to do it properly.
Your system is not conventionally set up coming from the supply line off the boiler. The boiler supply line comes off the top as it is but the next thing that should be installed is the AIR SCOOP, On the bottom of that air scoop is where the FILTROL should go with the cold water connected to it. The air scoop always goes before the RED FLO CONTROL VALVE. If you are using zone valves you do not even need that FLO CONTROL valve. That is used for another purpose.
If you go to Supplyhouse.com and put Filtrol into the search box options will come up and click on yours and you can read about it. For some reason I can't bring it up.
My problem and system are similar, no pressure and tried bleeding the baseboard and it seems like there's no water in the pipes..can you bypass the valves to fill the pipes before figuring out the problem? Getting cold..
You should first determine the reason for no pressure. You should have an automatic boiler feed valve on the cold water line coming into the boiler some where. It may have a lever or something similar to bypass the valve and let water into the boiler. If you lift the lever and get nothing then your feed valve is clogged or just defective and needs replacing.
Okay, I did test my boiler psi and the gauge is right what it's reading. With the heat running now, I'm seeing 9 to 10 psi. That's still low, it is heating up stairs fine but you can hear it gargling in the pipe.
The fill valve is on the expansion tank.
So if I set the tank to 20 psi that is what the boiler will have right? Yes, I know I have to drain the boiler down and remove the tank and fill it with air. What should the psi be, on a two story house.
the air scoop is after that red valve no idea. The zone valves are right after the air scoop. So your saying there should be another air scoop between the tank and that red valve?
1} Your gauge should read the same as your tank, (cold pressure).
2) Your Flocheck (Red Valve) should have been after the air scoop but as long as it's working it's not a deal breaker.
3) On your system you are right and your fill valve is a part of your expansion tank and the only way it works is to add air to the tank to increase cold water pressure in the boiler. If you increase tank pressure and your boiler pressure does not increase then your fill valve is either clogged or defective which is why I sent you a link to look at so you can see how it works and replacement parts at SupplyHouse.com.
4) If you hear gurgling then there is not enough water in the system and is only getting to the rads on the top floor because the pump is running. My guess would be that with the pump off you would not get water from the rads when bleeding.
5) You say your gauge is reading right but that expansion tank and fill vale come preset from the factory at 12 psi.so if your tank is holding at 20 psi then clean or change your fill valve.
In regards to your feeding the system through your FLOCHECK. That FC is a oneway directional valve and is meant to open only when the pump comes on. You will notice the arrows on the FC. Since you are not using your tankless coil you can open the FC manually by loosening the check nut on top and turning the red lever to open the valve. That may be why your boiler gauge does not match your tank. I'm not sure but manually opening that FC will do no harm in your case. When you pressurize your system open your zone valves to allow water to reach all zones. Technically it is 1 lb pressure = 2.31 ft. I find a good pressure is 18-20 psi with the wet rotor pumps which is what you have.
One more thing I noticed when I enlarged your pic is you have your tankless ports plugged. They should never be plugged and could cause internal pressure in the coil. Remove the plugs for safety sake. If there is any water in the coil it will boil out but that is normal.
Hi - Long time reader, first time poster. I have a B20 unit a home, electric only (no dual gas or oil). My boiler seems to make this loudish humming vibrating sound, even when its on 'idle' and not heating. We seem to really notice it when it turns on via heat demand, the vibrating humming noise almost pulses. I just went down to look at the boiler and the vibrations seem to come from the left hand side, the part with the tank. If I knock the front of the boiler (bottom RHS area) with my knucle (like a knock at the door typ of thing) the hummig stops. Any idea's?
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10-27-23, 06:46 AM
