Too much pressure in your boiler can lead to expensive repairs. Here’s what you need to know about managing boiler pressure.
Pressure gauge indicator in boiler-room
Boilers can confuse those who aren’t used to them.
They often have more fiddly bits than you’d find with a different type of heater. There’s even a pressure gauge, and runaway boilers are almost a film fixture.
If you know what pressure your boiler needs to run, you’ll better understand if you have issues. So here’s a quick guide to boiler pressure.
Ideal Boiler Pressures
Your boiler can either go too low or too high on the pressure scale. Both can cause your boiler to not function properly and to shut down.
To find the optimal pressures, consult the manual that came with your boiler.
But if that’s lost, most boilers are so similar the pressure differential between them is relatively minor. In any event, the usual cold pressure of a boiler should sit at about 12psi (pounds per square inch).
Most pressure gauges display different-colored zones. If the needle sits much outside the green zone, particularly on the high side, you have a problem.
Pressure Change Range
Pressure will change when the unit fires up the heat. In most cases, it should rise to about 20 psi while its heating element operates.
That’s optimal at normal temperatures. Pressure changes of a few psi one way or the other can be brought about by atmospheric conditions.
Most boilers are safe up to around 30 psi, at which point seals can begin to fail. Modern boilers aren’t nearly as dangerous as early steam engines , but you can still damage them and require costly repairs.
Provided your boiler stays in the 12-30 psi range, you’re in no real danger. But take a closer look if you bump up against the higher end of that range.
PSI Range Exceptions
There are exceptions to the generally accepted pressure ranges if you live in a multi-story home. A two- or three-story home needs to run slightly higher at 15 or so psi for two floors while an 18 psi is required for three.
That’s why keeping equipment manuals is so important. Failing that, a professional can determine the optimal range of your boiler by its model number.
For apartment buildings and other vertical applications, higher initial boiler pressures are required. But since the average person is unlikely to run into a commercial boiler, its pressure issues are always handled by professionals.
Immediate Action
While the occasional boiler explosion still occurs, modern boilers are remarkably good at not unleashing steam and shrapnel because pressures went a bit high.
For the most part, act quickly. Chances are you’re not in immediate danger. But it’s no harm to turn the system off until repairs are made. That’s less to avoid an explosion and more to limit further damage.
High-Pressure Shutdowns
High pressure can result from the boiler temperature being set too high. Higher pressures generally cause automatic shutdowns.
Modern boilers have built-in pressure release valves. These generally trip at 30 psi and release excess steam to bring the pressure back to normal.
It’ll also kick off the power to your boiler.
That can range from “inconvenient” to “aggravation” based on the time of year and your local climate. If yours goes off because of high pressure, power it down until a professional sees it.
On the other hand, if you’re in a normal temperature range but still have problems with exceptionally high pressures you’ll need to pick up the phone.
Low Pressure Issues
Low pressure will cause a boiler to have trouble reaching the right temperature. Ideally, the system will refill itself to 12 psi, but you can do it manually if the pump is down. That will keep the boiler operating until a technician arrives.
Low pressures are usually handled by repressurizing the boiler. You may still need an eventual fix, but the pump’s likely not working and you can buy some time with the simple procedure.
Professional Assistance
It’s important to know how your boiler pressure affects your system. The whole thing can seem complex, but what’s important thing is to make sure the gauge needle remains in the green.
Like all equipment, boilers eventually run into problems you’re not going to be able to repair at home. If you have trouble with any part of your boiler system, it might be best to call a pro.
Call (402) 731-2727 to set up an inspection today.
