Why does the pressure drop on my central heating boiler? Every few days i noticed its dropped so i top it up. Why does it keep dropping?? Thanks.
2007-01-29 21:27:48 · 8 answers · asked by S 4 in Home & Garden ➔ Other - Home & Garden
If the pressure is dropping as fast as you say then you have a leak. Bit like a slow puncture on a car tyre.
2007-01-29 22:05:39 · answer #1 · answered by Anonymous · 0⤊ 0⤋
What is the operating pressure supposed to be in your boiler? Boiler pressure does not have to be high, just high enough to insure positive pressure at the very highest part of the system with a small amount of extra pressure, like 5psi, to be sure. Every foot of heigth above the pressure gauge equals .43 psi, so if your highest radiator is 20 feet above that gauge, you would want about 14psi. (20 x .43 +5=13.6psi)
What is the pressure rating on the pressure relief valve? You might be adding more than it's rated for.
The expansion tank might be water-logged.
Somewhere in the system is an expansion tank. Sometimes it's a diaphram type, where the air is separated from the water by a flexible membrane, and sometimes it's just a tank with air in it that is located above the boiler with one pipe that runs to it.
What can happen is that the tank becomes waterlogged and lose it's air cushion. The boiler comes on, and as it heats up the pressure goes up quickly because there is no room for the expanding water. Then the pressure relief pops off, dumps a bit of water, and closes. Boiler cools down, and the pressure drops to below where it was. Check the pressure relief area and see if there is any water near the discharge.
Check the expansion tank by tapping on it. It should sound hollow if there is air in it, but it will sound "dead" if it's waterlogged.
If it's a diaphram type, it will have a valve on it like a tire valve, and if you push on the stem with a small tool, and water comes out...you need a new one. If you don't know exactly what you are doing, you will have to have a plumber or good handy-person do the repair.
If it's a tank with no diaphram, you close off the pipe that goes into it, and drain all the water out of it...then close the drain, open the pipe.
Your system should have an automatic filler on it, that maintains pressure in the boiler. These are adjustable. Once the system is set up, you shouldn't need to do anything to it.
2007-01-30 00:12:56 · answer #2 · answered by roadlessgraveled 4 · 0⤊ 0⤋
I believe it is due to losses in the system and possible ingress of air; these losses may be from leaks in joints or through pressure release valves which are there to protect the system, air can get in through leaks or bubbles direct from the water supply.
2007-01-29 21:33:13 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Pressure drops over time, but if you're topping up every day, then you may have a leak somewhere!! Sorry!!
2007-01-29 21:30:04 · answer #4 · answered by Fluke 5 · 0⤊ 0⤋
you have a leak in the system ..check the pipes either sides of the rads when they are cold ..pipes tend to seal them self when hot .all so check the rad valves for leaks if non of these then you probably have a leaking joint some where
2007-01-29 21:44:34 · answer #5 · answered by boy boy 7 · 0⤊ 0⤋
Best get this fixed. Boilers don't like frequent topping ups.
2007-01-29 21:39:20 · answer #6 · answered by Anonymous · 0⤊ 0⤋
It is most probably the pressure relief valve that is faulty. Unfortunately these valves can't be repaired and it has to be replaced.
2007-01-30 10:10:26 · answer #7 · answered by Anonymous · 0⤊ 0⤋
there must be a leak somewhere. check the pipes
2007-01-29 21:37:53 · answer #8 · answered by Deep Thought 5 · 0⤊ 0⤋