I have a boiler that heats my house. It is approximately 10-15 years old. When the guy who sold me the house gave me a walk around to explain a few things he remarked that the boiler pressure was higher than he'd seen before. (the pressure was between 15-20).I was looking at it today and it was at 25, and I had the heat turned down to 60 degrees F, so it wasn't working too hard.It has an automatic water filling function, so that when the water gets too low it fills back up. (the water line is in the middle of where it is supposed to be.I've routinely, once every 2 weeks, drained some of the dirty water from the boiler to prevent build up.Is the pressure build up normal?Is there maintenance that I should have been doing for the past couple years.Any advice would be greatly appreciated.ThanksMark
Part of the yearly maintainence on a steam boiler is to clean the pigtail that the pressure switch is mounted on. The pigtail can get clogged with rust / sludge and have difficulty controlling accuratley. You'll want to do something about this, trying to keep the pressure below 10psi, 5psi is fine. Running at the higher pressure can shorten the life of the boiler, and cause the pressure relief to blow repeatedly, causing it to fail. It'd also be a good idea to blow the boiler and low water cut off down from time to time to remove any sludge build up. Also wouldn't be a bad idea to dump a can of boiler / rust treatment in once a year. Best of luck
I didn't see anywhere that the question asks about a steam boiler,and with the pressure that high I find it hard to believe that it is steam!! First stop draining water out of the boiler every two weeks.This is not like a hot water heater that is constantly getting new water in it to build up deposits.A boiler is a closed system.Every time you add new water you are adding minerals that will drop out of the water and cause problems.There is either a problem with the expansion tank or the pressure regulating valve.It is most likely the expansion tank,there are two types of expansion tanks one with a rubber bladder and one without.The one with the bladder in it has air on one side and the boiler water on the other it may have a hole in the bladder and is filling with water this will make the pressure go up too far when the unit heats.The other type of expansion tank doesn't have a bladder in it instead it just has a pocket of air at the top that is compressed when the boiler heats up.This type of expansion tank will need to be drained periodically to refresh the charge of air because the air will dissolve into the water over time.When the boiler is cold it should be at 12-15 psi. when it heats the pressure will go up.It should be below 25 psi.when it reaches it's highest temperature.This will give you at least a 5 psi.cushion before the relief valve opens at 30 psi.
The pressure reading is too high. Check the pressuretrol (cut-out ) setting .It should be low. Nearly all residential steam systems should heat on ounces not pounds. Take apart the coiled pipe ( PIG TAIL ) that the control mounts onto and make sure it's not clogged with scale. Make sure that the gauge shows zero on a cold boiler, because the gauge could be faulty. I don't mean to be long winded but it could mean it's time to service (replace ) the vents on the radiators if it's a 1 pipe system (1pipe going to radiator ), or the steam traps on the rads if it's 2 pipe.
it sounds like you have a steam system. that much pressure build up could be very dangerous. most steam residential systems don't go past 5 psi. it's very possible that the pressure guage is broken, but more likely the pressure cutout switch is bad. from the same tap that the pressure guage is in there should be a coutout switch that will allow you to adjust the pressure of the boiler. this will have a pipe going into one end and an electrical wire out the other. this unit will shutoff the furnace when it get's to the desired pressure. I would check that first. if it's set to 3PSI and the boiler is getting up to 25, then there's something wrong with it.
