Hot water tank only supplying warm water...

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Old 03-11-13, 01:01 PM
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Hot water tank only supplying warm water...

Hey everyone, I'm new to the forum but not DIY projects - please be gentle with me!

I've got a Weil-McLain Gold Oil boiler that has a single circulator supplying 3 "zones" - 2 house loops and a hot water tank. I recently had to pull out two old aluminum fin baseboards and solder in new ones (and yay! No leaks at 25 psi!) however, I've had a nightmare of a time getting air out of the system that was introduced when I removed the baseboards. Additionally, the water tank stopped supplying hot water and is now only providing very warm water and it takes a long time to produce even that.

I've closed the ball locks on both house loops supply and return side in order to try to isolate the problem with the hot water. I've bled the system at pressure and I don't think there is any air left in it. The solinoid valve opens when the tank calls for heat and the supply to the tank gets screaming hot after a minute or two. It takes a long time for the return from the hot water tank to boiler to get even tepid, but it does eventually get warm. The ball locks to the hot water tank are open, both supply and return sides. I can hear the circulator (a TACO 007-F5) doing "something" sometimes, a very quiet hum most of the time, so I think it's circulating but I can't be positive.

Is there a way I can isolate whether or not it's the circulator causing the problem? Is there something else it could be? Pictures or video to follow soon and pre-emptive thank you for anyone spending time reading this let alone replying with ideas!

 
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Old 03-11-13, 01:52 PM
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I believe that there is still an air blockage in the indirect coil...

at least that's what it sounds like.
 
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Old 03-11-13, 02:09 PM
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Okay, I'll give another shot at bleeding - I think I've spent about 45 minutes now just bleeding the HWT. Any tips or tricks you can suggest? What I've been doing is closing the return (to boiler) ball lock, shutting off the furnace, manually opening the return ball lock and solinoid, pressurizing to about 25 psi and letting it rip out of the bleed valve (located just above the return ball lock) and doing whatever it takes to maintain pressure trying to keep it above 20 psi or so.

PS - this baseboard replacement was supposed to take a day. Heh. Thanks for the reply!
 
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Old 03-11-13, 02:28 PM
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Yeah, what they say about "the best laid plans" huh?

Show us the pics... I want to see the valves you have, there might be another method to suggest.
 
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Old 03-11-13, 04:33 PM
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Alright, forgive the lingo if I've got some terminology wrong, this weekend has been a crash course on boiler operations.

https://www.youtube.com/watch?v=3sZLXGMEbZk
 
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Old 03-11-13, 05:20 PM
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Most excellent 2 minute tour! Thanks, tells me what you need to know.

OK... here's what you need to do.

Shut down the boiler and let it cool to 100F or less.

At 1:03 in the vid, there is a ball VALVE just below the drain on the return with the hose on it.

CLOSE that ball valve below the drain.

On the PRESSURE REDUCING VALVE there is a lever on top. This is a FAST FILL LEVER. You will be operating this lever by lifting it to temporarily bypass the regulating function. You want a FAST flow through the pipes.

MANUALLY OPEN the ZONE VALVE (solenoid valve) for the water heater.

OPEN the drain with the hose.

Go to the PRESSURE REDUCING VALVE and LIFT that lever until there is no more air exiting the drain.

Release the lever and then CLOSE the drain.

OPEN the ball valve below the drain.

Return the zone valve to AUTO position

This should do it for ya...
 
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Old 03-11-13, 05:24 PM
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You can repeat this process for the heating zones if you feel there is still air in them as well.

The idea of CLOSING that valve below the drain is to prevent the water entering the system from taking the path of least resistance through the boiler itself and never even flowing through the zones or the water heater.

Closing that valve puts up a roadblock and causes the water to take a long detour through the pipes rather than the shortcut through the boiler itself.

This is why you had so much trouble also with the heating zones.

That drain and ball valve together are called a 'PURGE STATION' by the way.
 
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Old 03-11-13, 05:25 PM
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By the way, that's a pretty nice install. Whoever did that knew what he was doing!
 
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Old 03-11-13, 05:29 PM
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Another way to think about it if you are familiar with Zen Buddhism...

BECOME THE WATER.

Then, think about where you would go if you were the water...
 
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Old 03-11-13, 05:51 PM
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Thanks for the advice, I'll definitely keep trying it. Terminology aside, I've been doing exactly what you're suggesting for a while now and still can't get anything better than warm water (i.e. closing the ball lock below the drain, blasting water through it with the PRESSURE REDUCING VALVE - thanks for that!). I actually re-read your directions three times hoping I missed something..! Drats. I "think" the house zones are clear but I do need to run heat to them to check. First things first, though, hot water.. I need me a shower!
 
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Old 03-11-13, 06:01 PM
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Is the a WM indirect? I believe they have a jacket no? Is there a air vent on top of it?
 
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Old 03-11-13, 06:29 PM
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My beautiful, adoring, loving wife (who might or might not be monitoring this thread ) pointed out that I was not allowing the boiler temp to fall to 100F; I've been starting the purge around 185-ish. I don't know if this makes a big difference in results, but I decided (with maybe a little coaxing) to shut down the boiler and let it sit a while after this last 20 minute purge attempt where not a single tiny bubble came out running the system at around 25 psi.

While I was down there, however, I decided to see what would happen if I opened the house loops. I figured, if they heat up at the same rate as they did yesterday when the circulator was supposedly powered up and running, it would strongly imply that the heating I succeeded at restoring yesterday to zone two was in fact a result of convection rather than the circulator working. Sure enough, those zone supply pipes are heating up at the exact same rate. Slow. Just like the water heater supply pipes.

Thoughts on circulator being seized? All it does when powered on is make a sort of electrical hum and it gets pretty hot, pretty quickly.
 
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Old 03-11-13, 06:43 PM
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Yes, it's a Weil-McLain Gold 40 with an "Automatic Air Vent" on top that I can't seem to really do anything with..
 
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Old 03-11-13, 08:43 PM
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Well if the circ aint working you would have no heat either.... So from when you posted and 8 hours later I would think you would be cold in NY......


I would go with the circ at this point.......


Your poor wife....... Next gift will be an electric blanket for her...aye!!!!
 
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Old 03-11-13, 09:24 PM
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That boiler has the outlet either coming from the side or it has an internal nipple that extends downward inside the boiler. As a result air collects in the top of the boiler and the automatic air vent is needed to release that air. If that air vent is not working you could actually have such a low water condition as to not being able to "push" the water to the circulator pump and yet still show a normal pressure on the boiler.

You NEED to make certain that you do not have a huge air bubble in the top of the boiler by removing the "tire cap" on that air vent and pushing the pin to ensure that you get a solid stream of water. Let it "blow" for several seconds to be sure it isn't just expelling a small amount of trapped water.
 
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Old 03-11-13, 09:25 PM
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Correct; no heat but we've also got a wood stove that is fully capable of heating the house. We only rarely used the boiler for heat this year, mostly hot water. Going to buy a replacement circulator tomorrow and report back after it's in. Thanks!
 
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Old 03-11-13, 09:36 PM
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That air vent on the top of the boiler is open yeah!!!

As Furd stated that air vent on top that 1/2" pipe in an internal air seperator.

I dont think you have an issue there as its just a internal scoop..... Or high point....


As far as the circ...if its humming it should not for long. It should have a thermal cut off if it over heats. Then as it cools it will hum again.
 
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Old 03-11-13, 09:36 PM
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Check the vent BEFORE replacing he circulator pump!
 
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Old 03-11-13, 10:22 PM
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Vent blew copious amounts of water, zero air. Thanks for the reminder to check it.
 
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Old 03-12-13, 06:20 AM
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What is the full model number of the pump?

If that pump has an INTERNAL FLOW CHECK and is mounted in the vertical position, it is possible that the pump itself is 'airbound'. The internal flow check will/can prevent it from pumping... BUT...

Since you have been forcing water through it manually by purging the system this is quite unlikely.
 
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Old 03-12-13, 08:37 AM
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It's a TACO 007-F5. I'm going to go ahead and pull it off right now..
 
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Old 03-12-13, 08:56 AM
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circulator

Is it possible some debris got into the system from the baseboard replacement, and ended up lodged in the circulator? Steve
 
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Old 03-12-13, 12:45 PM
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Getting ready for a nice hot shower as I write this!

Swapping out the circulator for another identical one (and flushing air after installation before starting up the pump) did the trick - screaming hot hot water in 20 minutes and heat to all zones! Woot! ..A mere 4 days after changing baseboards, hehe.

A huge thank-you to everyone who read and replied to this thread and added incredibly helpful insight. My wife (and her cute-but-delicate-nose) thank you too! Phew! I stink!
 
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Old 03-12-13, 01:15 PM
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Cool... Good job. Glad it was an easy one....
 
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