On my home forced hot water heating system, the upstairs zone will not stop circulating heat.
I want to rule out a few factors. One of them is trying to figure out this valve:
Any takers? C'mon! it's a picture game!
Marc
Accross the pipe; meaning perpendicular or at a 90° angle?
- If its down low it might just be to drain the system.
It's a purge valve at the bottom. I'm more interested to see which setting on the tab or what Richard calls the ball functions to close it.
My larger issue with this zone is that it is always on when there is hotwater in the furnace. I first thought that it was a bad wire in the thermostat wire running up to the room where the zone is exposed. ie. two wires rubbing, but I tested first the ohm reading and there was no reading which means there is no contact between the two wires going up to the room.
I have even spliced the wire near the furnace so I could touch the two wires and hear the pump relay click and the pump operate (just as a thermostat would do).
So with the pump not pushing water to the zone, I am still getting hot water forced up into the zone. I don't see how this could happen.
I am hoping to find the problem and avoid a plumber visit.
Thanks for your replies and more are encouraged...
The small valve, to the left of your photo, is likely a ball valve as others have suggested. When the handle is parrallel to the valve body its on, when its perpendiculat yo the valve body its closed. All 1/2 turn valves work this way. you will see them in gas applications to. Sometimes its not a handle but just a ridge but the same holds true.
Looks like a combination ball valve and globe valve, with the ball in the open position. Turn the ball handle across the pipe to stop the flow.
Gravity feed. Hot water systems were designed to run without any pump at all, at least in the old days.
Yes, if that's it you can prevent it by installing an "anti-thermosyphon valve" which in the olde days we called a "gravity valve". It's a weighted check valve which remains closed and blocks the weak thermosyphon pressure differential but gets lifted opened by the higher pressure created by the circulating pump.
Go here:
HTH,
Jeff
I would guess the small valve is for controlling flow amount, The larger valve might be for bleeding air out of the system if this valve is at a high point of the system? If its down low it might just be to drain the system. Could it be to isolate the pump for replacement or service ?
It's pretty clear to me that you have a combination ball valve (tab on left, low profile) and a drain valve.
Neat gadget, I've never seen one in person. But it looks useful.
As photographed, the ball valve is open. Or, should be open.
If you have multiple circulator pumps, rather than zone valves (sounds like you do from previous posts), there should be check valve in each leg, otherwise hot water will circulate (in the reverse direction from normal flow) in the off zone(s) when any other zone is running. Sometimes the check valves are built into the circulators, but usually they are separate. If this just started happening, you may have a failed or stuck check valve. If it's always done this, then you need to add the check valves. They are usually right above or below the circulators. Get the spring loaded ball or cone type with neoprene seats, otherwise they make all kinds of noise. Be aware that adding the check valves will complicate purging air when filling an empty system.
HTH,
Paul
Jeff & Paul,
You clued me in to this part of they system - I found another valve on the send of this zone.
It was not shut all the way - I could tighten it a few turns atleast. With that I tested the system with the following:
With the pump not pushing flow (thermostat not engaged..) I Caused the furnace to heat the water and checked for change in temp beyond that point in the zone.
Fixed.
Exploring further around the furnace and hotwater tank, I noticed another one of these valves that was tightened all the way. This one was going into the hot water tank next to the furnace which is kept at tempurature by electric.
Thanks for your input on troubleshooting this.
marc
It's hard to give specifics without knowing the detailed layout of the piping. In general, there are two ways to purge a system, gravity and forced-water.
Gravity purging is when you just open the feed water valve after a shutdown, let the system fill with water as best it can, and then purge the air using the bleed valves that should be provided at the end of each radiator, or at least at the high point of each loop. In theory, all the air in the system will rise to the highest point where is removed using the bleed valves. Generally, the bleeding process should be repeated over a few days or weeks until all the trapped air is removed. Gravity purging usually works fine. You can run into problems, however, if the piping design is such that there are high spots without bleed valves or air vents. In other words, if a pipe goes up, over, and down without there being a bleed or automatic air vent, then an air pocket can form in the loop, and the circulator may not be able to lift water over the loop. Usually, these kind of loops are avoided by proper piping design. You sometimes see them when there are floor level radiators in the basement with the boiler.
More common are air pockets caused by sloping or sagging piping, where you can get a local high spot without a bleed. Unless severe, the air will usally eventually be cleared from these during normal operation.
I mentioned that check valves can complicate purging because they by limiting flow to one direction, they can create air pockets that can not easily be eliminated. Again, very system specific.
A more positive, and faster way to purge a system is forced-water purging. This requires a feed valve with a "fast-fill" bypass, or another way to provide full water pressure to the feed side. (such as a hose fitting). It also requires a drain valve at the low side of the piping (not the boiler drain valve). Specifics are very system dependent, but the idea is to use get full house water pressure flowing through each loop in the system, one at a time. This is more effective at clearing air pockets than gravity purging.
To make an already too long story short, if all you did was lower the water level a little to work on a radiator, and you've got a well designed system wth no severe blind high spots, then gravity purging will probably work fine. If the zone seems to get hot quickly, and gets hot enough, and you don't hear a lot of gurgleling noises, chances are you are fine. Just repeat the bleeding process several times.
You might look for a copy of "Modern Hydronic Heating" by Siegenthaler at your local library. IIRC, he has a whole chapter on purging air and correcting air entrapment problems.
HTH,
Paul
Paul:
What precuation/procedure should be used when purging air from a single zone heating loop that has the check valve located immediately at the hot output of the (Peerless) boiler ?
I just went through dropping the boiler water level so that a baseboard heater could be replaced, and I am not certain that the loop is fully purged of air.
Thanks.
So you did a kind of forced water purge. Generally, I don't run the circ or boiler while purging. The principle is the same, you want the water to flow in the fill valve, through the loop, and out the drain. Run it until it runs clear, doesn gurgle or sputter, etc., close the drain, close the fill, and you're good to go.
When everythings on one level, you don't have a clear nice high spot to bleed, so forced water is a good way to go.
Sound like you did just fine.
Paul
The url wouldn't fit so,,,
-zero
Paul:
Many thanks for your explanation and information. I am sure that it has helped me. I will look for that book at the library, also.
In my case, the replacement baseboard heater is the first in the series loop. This new unit is the only one that has bleeder valves installed (all other heaters lack bleeder valves). And, all units are on the same (floor) level.
The refill procedure used was to open the system supply feed valve, close the boiler drain valve, and then open the drain valve located above the water circulator; set the thermostat for a high room temperature, then watch for sputterring water flow at the end of a garden hose directed to a dry well. The supply pressure regulator has a handle marked "FAST FILL", and that was used also operated to try to keep the pressure level up as indicated on the boiler PSI gage.
When I felt a hot pipe at the circulator I felt that the system was purged. However, I will repeat this process a couple more times. Now that the new baseboard radiator includes bleeder valves, I may open those.
Thanks again.
My heating guy sticks the drain hose in a bucket. Easier to see when the air stops coming out.
It also gives a good visual aid to the homeowner.
Spirovents are about the best there is, but they do fail.
SOunds reasonable to me. Sitting here in a cold house, I'm thinking of starting up the furnace (well it is used for hot water too). ;-) Question: Every fall when I first turn on the heat the system is full of air. Where does the water go? The system is pressurized to ~14lbs, so it can't be going back into the city supply (60ish lbs.). I dont' see any leaks and I'd expect to see water when it's pressurized.
Maybe I'll add that next time I drop the system (need to add some valves goign to the upstairs bathroom anyway).
Thanks!
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.