Purging air from boiler
#1
11-12-08, 05:42 PM
Purging air from boiler
Hello,
I have a lot of air in my heating system and would like to purge it myself, BTW it's a 2 zone system. I've never done this before so if someone could possible give me detail instructions that would terrific. Here are the pic's of the beast.TIA.
I have a lot of air in my heating system and would like to purge it myself, BTW it's a 2 zone system. I've never done this before so if someone could possible give me detail instructions that would terrific. Here are the pic's of the beast.TIA.
Last edited by Strom2; 11-12-08 at 05:57 PM.
#2
11-12-08, 07:10 PM
First off, I'm sure you realize that the gaskets on the pump flanges need to be replaced ...
Is there a pressure gauge on the boiler ? What does it read when the boiler is COLD and then when it's HOT ?
I don't like sideways mounted pressure relief valves... I would mount that on an elbow so it's vertical. Mounted like that, 'crud' can build up around the seat and cause problems.
The brown bell shaped thing on top of the boiler is your feed water regulator. To the left of that is a MANUAL feed water valve. Is that valve open, or closed ? It needs to be open for the following purge procedure, and if it's closed, it may be because there's a problem with the feed water regulator.
There is a brass can with a 'tire cap' to the right of the feed water regulator. That's a float type automatic air vent. Is the cap on the top of that tight ? or is it loose ? It needs to be loose to allow the air that it might trap to be vented. If loosening the cap allows water to leak, that part should be replaced. The cap should be loose during normal operation.
If it has been a while since the air pressure in the expansion tank has been checked / adjusted, now is the time to take care of that routine maintenance also.
Do NOT do the following until we've verified that you have proper pressure in the system ... so check for a gauge on the boiler first, and let us know what it reads. There may be something else that needs to be done before purging the zones.
On the three return pipes, each has a drain, and a shutoff valve. To purge the air from the zones, you would shut off and let the boiler cool to under 100°, connect a garden hose to one of the drains, close all three of the shutoff valves. Direct the hose to a drain. Open the drain valve with the hose on it, and lift that lever on the feedwater regulator. That will feed water at a faster rate, pushing the air in the zone out the hose. When you get a steady stream of water, move to the next ... do all three.
Is there a pressure gauge on the boiler ? What does it read when the boiler is COLD and then when it's HOT ?
I don't like sideways mounted pressure relief valves... I would mount that on an elbow so it's vertical. Mounted like that, 'crud' can build up around the seat and cause problems.
The brown bell shaped thing on top of the boiler is your feed water regulator. To the left of that is a MANUAL feed water valve. Is that valve open, or closed ? It needs to be open for the following purge procedure, and if it's closed, it may be because there's a problem with the feed water regulator.
There is a brass can with a 'tire cap' to the right of the feed water regulator. That's a float type automatic air vent. Is the cap on the top of that tight ? or is it loose ? It needs to be loose to allow the air that it might trap to be vented. If loosening the cap allows water to leak, that part should be replaced. The cap should be loose during normal operation.
If it has been a while since the air pressure in the expansion tank has been checked / adjusted, now is the time to take care of that routine maintenance also.
Do NOT do the following until we've verified that you have proper pressure in the system ... so check for a gauge on the boiler first, and let us know what it reads. There may be something else that needs to be done before purging the zones.
On the three return pipes, each has a drain, and a shutoff valve. To purge the air from the zones, you would shut off and let the boiler cool to under 100°, connect a garden hose to one of the drains, close all three of the shutoff valves. Direct the hose to a drain. Open the drain valve with the hose on it, and lift that lever on the feedwater regulator. That will feed water at a faster rate, pushing the air in the zone out the hose. When you get a steady stream of water, move to the next ... do all three.
Last edited by NJT; 11-12-08 at 09:35 PM.
#3
11-12-08, 07:40 PM
NJ Trooper, thanks for the response, here are the readings 15(cold)when off or non circulating and around 20(hot)when circulating, temperature is around 130-140 range.
#4
11-12-08, 09:36 PM
Check the other two questions above ...
If the feed valve is open, and the cap on the air vent is loose already ...
then go ahead and try the procedure... the pressure looks fine.
If the feed valve is open, and the cap on the air vent is loose already ...
then go ahead and try the procedure... the pressure looks fine.
