I was called out today on a boiler in a hydronic heating system that was limiting out.
The house was being remodeled, and a plumber had emptied the water out of the system while doing some work on the baseboard heaters. He didn't bother filling the system.
This system had probably never been opened since it was built 17 years ago. I couldn't get the water to circulate in either of the two upstairs zones (bad zone valve wouldn't open for the basement).
I purged all the air that would come out of the purge points until I got all water. The B&G 1/12 HP pump was cranking away fine. The isolation valves are all open, as far as I can find them anyway.
I'm wondering if it needs more places to bleed out air? There were a couple of purge points on each pipe run.
This has stumped me so far. I invite comments on what I may be missing.
You need a purge valve and a boiler drain.
You can use a small sump pump to circlate water through the boiler.
I will post a pic tommorow if you need one.
Sometimes it not a air problem,flow could be the problem.
I would go and check just what the plumber did to the distribution system.
Did he remove any baseboard,did he add any baseboard.One
of my favorite.. they piped the series loop up and over a doorway then back down.
I agree with capt kman a purge scoop is in order and,you
need to look at the distribution and see where you can offer some improvement where money spent now will save plenty of dollars on the service side.
Seattle If I may offer just two books that will help you gain the knowledge to spot the things or problem with h20
heating system.Also keep in mind not only do they help you
there but,they bring money in as well.
Howe Come? This book has brought me in 2000 time more money then it ever cost me.
Pumping away..this one I'm very fond of because a good friend gave it to many years ago when I very depress with spending to much time chasing air problem.
Seattle if your money tight I'll make you a deal.I'll send you both these books if you promise me you will send me two
dollars on every upgrade or time save on every job you do.
Heck being I'm so kind I'll place a limit on it of lets say seventy five dollars.
http://www.heatinghelp.com..books and more.
You might also check to see how much water pressure you have in the boiler.You'll need a minimum of 18 pounds to get the water up to the second floor.There is a formula to use on how much water pressure you need to reach 2nd floor,but it escapes me.I usually use a pump to push the water up to the second floor,then when I get good flow,I open the auto-feeder wide open while purging to make sure I got all the air out,then let the auto feeder work until I reach at least 18lbs.
Maybe a stuck flow check?
I backflushed a mouse out of a 3/4 copper zone to an addition once. Musta crawled in while pipe was open.
Does that B&G pump have a pump coupler? I had a job that the coupler was cracked and looked like the pump was working but it was not.
Thank you all for the generous comments.
I've visually inspected the B&G pump carefully, and it's turning fine. Always aim for the easy fix first, right?
Simpleman ---I wanted to check out the book you recommended, but your link doesn't work.
I checked out the system visually, and couldn't detect damage done to the system by the plumber. But it's not wise to underestimate the creative genius of a plumber, so almost anything is a possibility. Based on the comments received, that's the thing that's most likely to be the cause of the problem, I'm guessing.
Another thing is that there are three zones, none of which are passing water. One zone had an obviously defective zone valve, the other two valves open without passing water. Even the mouse would get through the 1.25" or larger pipe and plug up one or the other zone valves I'd suppose, rather than both.
One other thing struck me as peculiar. There is no automatic water feed using a regulator and no check valve, just a water stop directly off the domestic water line. When I open that valve, I'd expect to hear water running strongly into the system, pressurizing it to the point that a relief valve would open.
Instead, there is sometimes some water flow, but it stops as if the pressure on the system is equalizing with the domestic water pressure. I verified that there is good water flow through that valve, but I didn't measure the pressure on the system at that point.
Both pressure gauges on the system appear to be frozen up and don't move under any conditions, limiting the information I have while working on the system.
As I think about it, I could have installed a gauge on the water stop beyond the water fill valve, but I didn't think of that at the time. That would have given me the actual pressure on the system at that point.
Thanks for the comments so far.
Maybe the plumber has the loops tied back into themselves so there is'nt a way for the fluid to circulate.
there may be some shut of valves down stream that are closed on the zones. i have seen a lot of older systems where the installer would put stops in some very strange places. if gate valves were used the gate may not be opening and or is broke off the stem. you may also find a feeder installed down stream also. check the pipeing again real closely.
This link should work.
The "pumping Away" book is on the third page, just scroll through the items.
You should purge one zone at a time to minimize air entrapment. Hook a hot water pressure guage to the boiler drain to get actual pressure on the system. I have mine hooked to a washing machine hose so I don't have to strain the old bifocals standing on my head to see what is going on. Heat up the system then shut it off to bleed I've found this gets more air out Quicker.