Adjusted auto water feeder due to high pressure but had no effect

[Shivers20]

Utica Boiler MG125 HD hot water boiler. Auto water feeder installed on hot water supply coming from the hot water tank.
1. Boiler pressure gauge was at 25 psi and 90 degree temp.
2. Drained boiler down to 0 psi to remove old air vent
3. Replaced old auto air vent above expansion tank because it was spitting water
4. Adjusted auto water feeder to reduce water going into the boiler by a significant amount
5.Pressure still sitting at 22psi, the auto feeder valve cannot be adjusted/reduced anymore.
6. I shutoff the auto water feeder valve and drained the boiler, dropping it down to 12psi
7. Okay to have the auto feeder valve shut off as long as the boiler isn’t losing water?
8. Haven’t fired up the boiler yet.

 

[Fitter30]

Boiler prv isn't made for hot water supply. A prv can't be used for boiler low water safety so it can be valved off but the low water control should be checked out to make sure it works.

 

[Sponsor]

 

[Dana]

Utica Boiler MG125 HD hot water boiler. Auto water feeder installed on hot water supply coming from the hot water tank.
1. Boiler pressure gauge was at 25 psi and 90 degree temp.
2. Drained boiler down to 0 psi to remove old air vent
3. Replaced old auto air vent above expansion tank because it was spitting water
4. Adjusted auto water feeder to reduce water going into the boiler by a significant amount
5.Pressure still sitting at 22psi, the auto feeder valve cannot be adjusted/reduced anymore.
6. I shutoff the auto water feeder valve and drained the boiler, dropping it down to 12psi
7. Okay to have the auto feeder valve shut off as long as the boiler isn’t losing water?
8. Haven’t fired up the boiler yet.

Is the expansion tank a bladder type?

If yes, does the Schraeder valve (like on a car tire) spit water when you press the center pin? If yes, the bladder is leaking and the expansion tank has to be replaced.

If replacing the expansion tank the air pressure needs to be pre-charged to the target system pressure +1-3 psi. (eg,:if the system is going to be pressurized to 12 psi when cold, set the air pressure to 12-15psi before installing it. It can still be properly charge post installation but it's a more cumbersome process.)

Auto-feeders are a "solution-problem", creating as many problems (or more) as they solve. It's fine to isolate the system from the potable supply after pressurizing the system. If the system develops a leak you'll be hearing about it either from flash-boil sizzle/bang at the boiler, or cavitation noise at the circulator pump long before it's a hazard.

 

[Jadnashua]

Or, if your boiler has a low-pressure switch, it will shut itself down...needing to regularly add fresh water to keep the pressure up is a sign of a problem you really need to find and fix.