Baseboard bleeding

shifty23

Hey everyone, I’ve looked around a few different forums and pages and cant find a setup like mine. I replaced the expansion tank and need to bleed my baseboard radiators but none of them have bleed valves. Im just not sure which hookup to attach the hose to, theres 2 options i have to choose from. I will attach pictures for reference. One picture is the whole setup with shut off valves, zone valves (which look to be in the closed position) and the last is the 2 spigots that im unsure of which to use. Any help is appreciated!

shifty23

EdTheHeaterMan

You have plenty of valves so you should be able to purge the radiators, assuming you have the copper tube type baseboard radiators. Venting with air vents on each radiator is for old cast iron radiators.

This pipe with the green arrow is probably the fill pipe.. If that is the system fill pipe (not the best location by the way) then following that pipe back to the source of the water, you should see a pressure reducing valve or automatic water feeder. Please verify that by looking for one the there devices. these are the most popular ones, Apollo, Watts, Taco, or B&G (some of the B&G valves are RED)

Let me know and I can talk you thru the purge process.

EdTheHeaterMan

After a closer look, you have the Watts auto fill valve with the fast fill lever on the top.


The concept here is to build up about 25 PSI on the gauge then open a valve to force the air from the loop. in order to do this you must close off several valves in order to make the loop you want to purge the only path for the water pressure to go. This water pressure will force the water thru the 3/4" pipefast enough to push the air out ahead of the water, even if the air needs to go down a vertical pipe. If the water is moving too slow it will not push the air out. It will just bubble up to the top, so you need to build up the pressure before each purge.

I am going to look at your pictures and draw a diagram for you. This will take about 30 minutes. Please be patient

shifty23

Awesome thank you so much! No rush on the diagram I’ll be patiently waiting 

EdTheHeaterMan

SORRY FOR DELAY. Your piping diagram took longer than I thought, and there are several background pipes that are hidden by pipes that are in the foreground. There is one problem that I can not solve with the information in your photos But we will get to that at the end.
First lets label all your valves and parts that are involved with purging.


The valves are numbered all the other parts are labeled with letters.
Now here is the diagram with all the labeled

Now we can look at the piping as a complete system. There are 3 zones that I see (that means 3 thermostats). One of the zones is operated by the Black Circulator pump thru supply pipe that tees off to the flo-check valve B. From there the heat flows to the Black circulator thru the yellow pipe E. The black circulator pumps the return water back into the boiler to be reheated. I am not concerned with what type of radiators are on that zone.

Next illustration is how to force the water to purge air from Zone 2. That Is done by placing a garden hose on valve BD2, Closing valves 1, 3, 4, and 5. Then manually open zone valve C. Now look at the diagram to see the only path for the water is to enter the boiler thru valve 9, and follow the path on the AQUA color arrows and exit thru the boiler drain valve BD2.

Now comes the fun. With BD 2 closed and valve 9 open you will lift the fast fill on the feed valve A and watch the pressure gauge on the boiler rise to 25 PSI. When you get there, open BD2 to flush out the water and air from that loop. If needed to be sure, you may need to close BD2 and watch the pressure rise to 25 PSI again, then open BD2 to purge the remaining small bits of air in that loop. Once the water is flowing steady with no more air bubbles leaving the hose, you close valve 9 first, then close valve BD2. You have just purges Zone Loop 2.

Now comes the part I can not resolve. On zone 1 you will do the same thing with valves 2, 3, 4, and 5 closed and the zone valve C manually open. But there is a problem that I can not solve. Look at this illustration: There are 2 paths for the water to flow once the water goes thru the Zone Valve C. The water will take the path of least resistance and purge that loop (in this illustration that would be the short pipe RED radiators F) then return to the BD2 purge valve.

EdTheHeaterMan

The Blue pipe/radiators G will still have air in them. There may be a valve located somewhere in the piping system for Zone 1 on the Red Pipe/Radiators that will be able to be closed in order to make the water go the the Blue pipe G. This valve on F will need to be closed to force the water thru G .
Then the valve on G will need to be closed to force the water to purge F. I hope you find those valves.
...and if you do let me know where they are and I will update the process for zone 1

EdTheHeaterMan

Now if Zone 3 is also baseboard loop, you can purge it the same way. The closed valves are 1, 2, 3, 5, and 6. Valve 4 is open and the garden hose is placed on BD3.

Now comes the fun again. With BD3 closed and valve 9 open you will lift the fast fill on the feed valve A and watch the pressure gauge on the boiler rise to 25 PSI. When you get there, open BD3 to flush out the water and air from that loop. If needed to be sure, you may need to close BD3 and watch the pressure rise to 25 PSI again, then open BD3 to purge the remaining small bits of air in that loop. Once the water is flowing steady with no more air bubbles leaving the hose, you close valve 9 first, then close valve BD3. You have just purges Zone Loop 3. This will only work on baseboard that is made with copper tubing. The type of baseboard the has the copper tube with the aluminum fins. If there are convectors or radiators other than copper tube radiators, the purge will not work and you will ned the use the air vents on the radiators to vent the air.


After all the loops are vented or purged the best you can, you need to put everything back to operation mode. The zone valve manual levers are returned to the up or automatic position. BD2 and BD3 are closed and capped. Valves 1 thru 8 are opened. The auto feed valve manual lever is returned to th down positio for automatic operation. Valve 9 is returned to the operating position you found it in. In most cases that is open, but can be closed. Open a boiler drain valve to lower the pressure to about 12 PSI. If you let out too much water and the pressure is below 12 PSI, then open valve 9 and let the water feed do the job of putting the pressure back to 12 PSI for you.

Once the cold water pressure is at 12 (12PSI to 15 PSI is acceptable) you can start the boiler and turn on one zone at a time to see if the circulator pump moves the heated water thru the house.

After you have done all that and you are unsuccessful, then you will probably want to call a plumber. LOL

EdTheHeaterMan

WARNING.

Keep your eye on the pressure gauge to be sure the gauge does not go over 30 PSI or the relief valve will make a mess on the floor. Put a bucket under the relief valve just in case. Turn off valve 9 if the pressure is getting too high.

between 67 and 70 feet on your gauge is equal to 30 PSI. Be sure to read the correct scale. If you only get the pressure up to 25 feet water column, then the pressure is only about 12 PSI. Not enough pressure to move the air out from the second floor.

shifty23

Wow, Ed, I can‘t thank you enough for such a time staking and detailed help guide. I have confidence I will be able to get this done thanks to your help. Clearly I’m not an experienced plumbing/hvac guy but I just bought my first house and am trying to learn as much as I can! Anywho is the attached picture the missing valve for zone 1?

EdTheHeaterMan

YES. we can call that valve 1F and that valve needs to be closed to purge the G pipe on zone 1

Now look for another valve on the pipe that goes in the other direction. If you find that valve, we can call that valve 1G and that valve needs to be closed when you purge pipe F. Of course valve 1F will need to be opened back up to let the water and air to purge thru pipe F.

I hope this helps.

EdTheHeaterMan

After a closer look, that pipe looks darker than the heating system pipes. That pipe may just be a cold water pipe on the potable water system. If it is on the heating system piping then it may be a valve for separating the 2 different loops of zone 1. If it is on the potable cold water pipe then not so much.

shifty23

Ahh yes you are correct that is a cold water pipe. I couldn’t seem to find a valve in that section of the diagram other than the ones pointed out. I will attach a few more pictures of different angles if that helps any. Just a quick schematic of the house, as you stated there are 3 thermostats. Basement, 1st floor and 2nd floor. The basement is half in-law suite which I'm guessing was added after they built the house so I’m not sure if any jimmy rigging may have been done to incorporate the heating system down there? 

EdTheHeaterMan

EdTheHeaterMan

This is the Tee fitting where the two different loops return to the boiler

EdTheHeaterMan

It appears that the basement heat was added to the zone with the green circulator by adding 2 zone valves. The basement goes in 2 directions after the zone 1 zone valve and splits. Those I have labeled F head off to one side of the basement and return from that same side. The pipes labeled G, go in the opposite direction and drop to the floor near the doorway that is at the bottom of the basement steps.

Are there any valves inside those radiator covers in the room(s) that is(are) heated?

And have you tried to purge the air from any of the other loops? Were you successful?

shifty23

Ok. Its all coming together in my head now. I have not purged anything yet, I work late and its dark and freezing by the time I'm home lol but hoping to get into it this weekend. So I failed to mention that the “2nd floor” is a refinished attic that I’m guessing was also added on some time after the house was built. So I sketched up a little diagram that I hope isn’t too confusing and it’s what I think may be going on. Is it possible that the first floor could not have a zone valve? From what I’m gathering it may not have one? Looking at the piping one is labeled apartment which is technically the basement and another attic which is the “2nd” floor”. I’ll attach my diagram and hope that answers this mystery. There are no other shutoff valves that i could locate. 

shifty23

So I think it struck me, the basement zone is divided in two which is why they run off of one zone valve, they each go into opposite sides of the in-law and then the attic is run off the second zone valve. So would the 3/4 valve B be my shut off for the main level?