Topic: Bleeding Furnace/Boiler of Air?

[DaveBarbier]

Any plumbers or furnace guys out there can give me a hand in this? I'm trying to bleed my furnace and I don't remember how. I mainly get my house with a wood stove but I just turned on the baseboard heat and I'm getting a lot of burbling and it's not getting warm. I have three zones, the basement is getting heat, but the middle floor and top floor aren't.

I had a guy out here a few years ago and he bled the system with a hose, bucket and flipping a couple levers in a particular order. I should have made a video of him doing it. I don't have any bleeder valves in the house on the baseboard heaters.

Hoping to get this done today!

Or if you know of a good forum where I should post this that would be good too.

[calj737]

Should be an expansion tank in the basement. Follow the plumbing from the furnace out, and up. I know you're "height challenged" so you may have to tilt your head back pretty far to see up high enough 

[DaveBarbier]

Found myself a stool and found an expansion tank. Here are some pictures of the system.

[strynboen]

you have a closed  pressure buttel melbrane system,,it have only  a small 5 litre expansion air bubbel. vith for kompressed air at 1,5 bar..so need only a small burst of vater in the system to get up to the running pressure ...thek the manometer..if there is missing pressure fill some vater in the system...but altså tap the air aut..its a balance...take air aut at the top points in the system...and fill varer inn to kompensate..and renember as the varet heats up..the pressure vil reise..so dont fill vater in a Cold system..to the maximum..it vill then go over maxium after its heat up

think the manometer(pressure meter) vill be over the pressure buttel..also thek the cirkulation pumps..you have 3..one for hot vater beholder..and one for cirkulation for radiators..the tirth..is a bit ??..in Europa ve dont use 3 pumps...can it be a sirkulation od hot drinking vater...so the hot tap have its ovn sirkulation..for fast hot vater tapping..

the old open expansion tank systems is easyer..just fill vater inn to it splach aut of the overrun line..but they is a bit costy..as the hot energy is vasted in the open system

[DaveBarbier]

Right, that all makes sense to me, but I don't know which levers to open or close.

The expansion tank has a small valve which takes a bit of air out of the system, but it can't handle a lot of air, from what I've been reading. If I have a lot of air in the system, like I do now, it must be manually bled.

[DaveBarbier]

On the left, there are three pumps (two greens and one painted black). Those are the zone pumps. Far left is top floor, middle is middle floor and right is basement. Above each pump is a valve I can turn to let air and water out for bleeding.

[strynboen]

the auto bleeders need a small copper vire pressed dovn..so the svimmer gets aktivated...just like a sohc kaburettorfloat valve..they are not realy Automatic...if there onlu are small air bubbels..i use to by pass them to get all air aut..try to find the konnektion from drinkvater tap..to the sentral vater system..there is a link..often a rubber line as most dont like the idea of a solid line..or they had use a garden hose ti fill vith..often there is glykol in the system....but not all have that..and to fill a bit vater inn the system ..it dont thange the 50%mix so just fill a bit vater inn..
if you open the drinkvater side first..and then carefull opens the heat system side..and let it slovly press vater in the heat system..then it can not to vrong..and thek the manometer..so you not go over the red line..you only need a few liters vater to get the pressure up
thek the sirkulation pumps are rotating..they like to grov stock..in the summer...in denmark there is a center hole to open..and put a schrevdriver inn to rotate the rotor...to brake them free..
try to find the top of the vhole system..of radiators and lines..there is a small air trap beholder vho holds the air trapped..and bleed there
oil heat systems are banned in denmark..the old must be used..but no new systems are build...ve use nature gas vood pillets and kollektive heat systems..vith 100 km of lines all over the land(denmark are small)

[DaveBarbier]

Thanks Strynboen, but I'm just not sure what I'm supposed to do with my system. Like which levers to throw. I'm trying to search for a good forum on furnaces and boilers but I'm not finding any specific ones. I'll join a DIY home repair one in the mean time.

[strynboen]

the prinsip is..fill vater inn inthe bottom...and leak air aut in the top..no fittling valvets or Black magig...the easy vay is just leak air aut up in the house somvhere at the heigest point...and hope there is pressure left in the airballon beholder to hold some pressure up..often there is pressure for more air escapes..so no need for filling vater in the systen right now..

..but you need to get some air aut..to make the vater sirkulate
så try to let some air aut..up in the house.

..you can not press air aut in the bottom..dovn at the burner..so konsentrate to find a air nippel/air trap somvhere up in the house..

.and you have heat right now...

[strynboen]

Right, that all makes sense to me, but I don't know which levers to open or close.

The expansion tank has a small valve which takes a bit of air out of the system, but it can't handle a lot of air, from what I've been reading. If I have a lot of air in the system, like I do now, it must be manually bled.

thats the air ballon..its must hold 1,5 bar pressure( at a emty vater system)...dont leak thet pressure aut..if you have done it..its a bit of a problem to reload it..but use a kompesssor can do the trick..its use a car/mc valve..its a closed rubber ball inside the matal tank..vork as a expansion ballon..normaly it ate filled vith air..before the sentral heating are filled vith vater..to get a korrekt 1,5 bar start pressure....if you have emtyed it...it need some kompressed air to vork..just try to give it a small blov..max 0,5-1,5 bar..or look at the type plate..for korrekt pressure

[DaveBarbier]

There are no bleed valves up in the house. The bleeding is done down at the furnace/boiler. I get the concept, and I guess I can throw levers around and see what happens, but there's a certain way to do this. That's what I'm trying to figure out.

Right now, no, there's no heat in the house aside from the wood stove.

[strynboen]

ok ..yes those 3 valvets..over the pumps..must be the key to get it aut..but it vill meed a lot of vater flov to press the air dovn and aut of the valve...så a big vater flow in the kettel is needet..to get a heigh float trough the system.to a strange vay of bleeding airn aut of the system..all radiator termostates must be full open(if there is any) to hold flow in the loop...this is not like any Scandinavia made heat systems.

[DaveBarbier]

Yeah it's an older system, but even some of the new ones are bled down at the basement.

[DaveBarbier]

Ok, I got it. I was able to call a friend's father who worked with furnaces and boilers. Easy peasy and I now have heat in all floors. Thanks for the help guys.

[Don R]

 Watch your pressure, sometimes a dose of air in a system has come from a failed bladder type expansion tank. then the pressure may increase as the system heats up. Watch for the relief valve leaking.
 
 I was on a service call once and the guy had replaced his relief valve with one for a water heater, 150 lbs relief pressure rather than the 15 lb one he needed. He built a bomb in his own basement.

[pmanning]

So, this is the kind of work I do for a living these days.  First, what kind of pressure do you have on the loop now? For multiple floors residential 20 - 25 psi usually is enough.  I didn't see a pressure gauge on your set up but that is the first thing to check.  Do not bleed air out of the expansion tank.   If the tank is in good order the air in that tank is to balance the expansion of heated water as you boiler cycles.

The pumps are on the return side of your heating loop.  With the pumps off and adequate pressure on your loop you should be able to bleed air out of each zone by opening the loop at or near the pump.  It may take a while to purge and you have to make sure that make up water is coming into your system as you bleed water/air off.

Good Luck!

[Don R]

 Not having bleeders on the fin tubes complicates things because adding water to flush also adds air. It seems he got it, so good deal as long as the pressure stays in the safe range.