Help bleeding Slant/Fin Heating system with no return drain valve ???

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Old 02-20-13, 09:46 AM
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Help bleeding Slant/Fin Heating system with no return drain valve ???

Over the weekend the pipe in our living room burst and we got a tech to come out and fix the leak. The tech didn't purge the system and will not come out again for free. I was dumb and this is the first time dealing with water heated baseboards. He gave me a key so I could purge the system myself. The heating system is working so far but there is definitely a lot of air in the system. You can hear the loud gurgling and banging noise in the pipes. I did research understand how this entire system works. The only problem is getting the air out of the system.

Current Setup: Manual water supply feed valve that passes to an Expansion tank then to the Slant/Fin boiler. From the Slant/Fin boiler there are 6 zones with Taco Valves and 6 return pipe. There is only 1 drain on the boiler itself and that is to empty the boiler. There is a bleeding valve on the radiators in each zone.

Alot of the methods provided in the forum does not apply to me.

Current PSI is ~15 and temp in the boiler is 65F. I do not see any aquastat gauge like some others.

I tried to close all the zone by turning off the thermostat and bleed one zone at the time using the key and a pan. The stream of water is extremely small and I am not too sure how long to let it run. I am definitely keeping an eye on the PSI and temp.

I am trying to get as much info I can to try it out this weekend. I only visit the house during weekends.

What is the best method to purge out heating setup like mine???
 
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Old 02-20-13, 03:23 PM
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Manual water supply feed valve
Meaning that you do not have a 'pressure reducing valve' that regulates the pressure to 12-15 PSI?

an Expansion tank
What type of tank? Large steel in the joists above the boiler? or diaphragm type (looks like propane gas grill tank)?

only 1 drain on the boiler itself
You say 'boiler itself'... does that also include the piping to and from the boiler then? Just one drain on the entire setup? (except for the pee bleeders on the rads).

Is there an 'air scoop' and automatic air vents on the system?

I think pics will help us if you can post some...
 
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Old 02-21-13, 08:02 AM
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Thanks for your response...I will go up this weekend and will take some pictures...


- manual supply feed valve : The system does not have automatic water feed if pressure drops. Do only way to increase the pressure is by manually turning on the Valve and feed watter into the system. The only way the pressure would drop is a leak, bleeding from the radiators or drain from the said of the boiler.

- expansion tank: looks like a propane gas tank - diaphragm type..

- only 1 drain on the boiler itself: there is only one valve on left side of the boiler, that will empty boiler including the water from the pipings. 1 drain for the entire setup(except for the pee bleeders on the rads).

not sure about the air scoop will need to check again but i think there is one on top of the expansion tank.
 
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Old 02-21-13, 03:04 PM
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The system does not have automatic water feed if pressure drops.
Is there a LWCO (Low Water Cut Off) on the system?

only 1 drain on the boiler itself
...bummer...

And it's at the bottom of the boiler, isn't it?

Sounds to me like you might want to schedule a little 'torch time' and add a 'purge station'.

I really like these:


image courtesy pexsupply.com

50615 - Webstone 50615 - 1-1/4" SWT Webstone PRO-PAL Ball Valve w/ Drain

These are what Webstone calls 'Tee Drains'. The inner ball actually has a 'tee' port drilled through it. Depending on which way the handle is installed determines which side of the valve the drain is connected to.

We can advise where you might want to install one (or more) of these when we see the pics...
 
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Old 02-21-13, 03:25 PM
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What is the best method to purge out heating setup like mine???
Let's see if we can come up with a few tips that might help without having to do some plumbing.

First, while bleeding, manually raise the system pressure as high and close to the 30 PSI relief valve setting as possible. (like 27 PSI or so). Raising the pressure causes faster flow and 'squeezes' the air bubbles smaller. Sometimes this gets them to move.

Don't assume that the pressure gauge is accurate, see:

http://www.doityourself.com/forum/bo...ure-gauge.html

The problem with the tiny bleeders is that you can't move water fast enough in the system to move the air bubbles along. If you get only water in the first few seconds of opening the bleeder, there is probably not much point in keeping it open. Air must be UNDER the bleeder for them to work... and if you can't move the water fast enough to move the air, well, it would be pointless to keep bleeding.

Try opening one zone at a time and call for heat... push the t'stat for that zone way up... let the zone valve open up and the circulator run. Bleed each zone this way. BE CAREFUL! The water will be HOT!

WATCH THE PRESSURE as the boiler heats up... if you turned up the pressure on a cold boiler, when the boiler gets hot the relief valve may spew. (see below *** for tips on servicing the expansion tank)

Repeat for each zone.

Let the system 'rest' for a while after the first round... then open each bleeder again with the boiler pump NOT running. If you are lucky, the bleeders will be located at 'high points' and the air will float up and collect under the bleeders while the system rests.

*** You might first want to service the expansion tank to give you as much expansion capacity as possible while doing this.

Read this to understand a bit about your expansion tank, and the service it requires. There are step by step instructions for checking and charging the air in the tank. If you do service the tank, follow the step by step to the LETTER:

http://www.doityourself.com/forum/bo...sion-tank.html

Even if this doesn't get all the air out, at least you will have something to do while you're there!
 
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Old 02-22-13, 06:07 AM
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Thanks a bunch... I was scratching my head when purging the air out the first time. Bleeders are so small, I wasn't sure how long to let it run before closing it. Even with the bleeders open on a radiator it takes a while for PSI to drop.

This will keep me busy the whole weekend.

----

I was thinking to drain it during summer and refill it. With this system is it possible to get all the water out and refill it properly? or maybe I should work on installing extra valve to make things easier.
 
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Old 02-22-13, 06:57 AM
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Draining and refilling is a "Catch 22".

You still have no way to purge the system of air.

After water has been in a heating system for a period of time, all the gases should be driven out of the water and vented to atmosphere via the air scoop and automatic air vent.

FRESH WATER contains a tremendous amount of dissolved gases (air)... when this water is heated the gases are released. This sometimes takes a period of time before all the air is driven from the water and released.

If the goal is to rid the system of air, you won't be doing yourself any favors at all by ADDING MORE AIR in the form of all that fresh water.

Your system needs to have a functioning air scoop and automatic air vent properly positioned on the piping, AND a method of 'purging' the existing air from the system.
 
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Old 02-24-13, 03:08 PM
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Updates:

Good news: is that I didn't do anything and the noise went away. Not sure what happened with the air inside the pipes. As soon I got there I raised the pressure from 13 to 20psi and turn on the heat for about 1hr in all 6 zones to get water circulating. I didnt realize that the noise was gone. I had to bleed some water out to drop the PSI back to 15, but because it was taking so long I left it bleeding thru the radiator nip and got side tracked!!! Fortunately nothing bad happen. I still do not understand what happen with the air from last week.

Bad news: is that 2 of the zones are not working. Seems that the thermostat is not calling for heat. I set the thermostat to 75F for couple hours and the room was still 55F. The only thing I can think of is that the Taco valve is shot?? I moved the valve from Auto to Open and hot water circulates fine. Is there a way to replace the Taco valve without plumbing??

Here are some pictures of the setup:




Here is the 6 zones. One of the zone that went bad is the bottom one, valve have a green cover looks much older than the other 5.







Expansion tank and the valve to feed water into the system.



Switch to shut off boiler and all the return lines:



This is what 2 of the radiator bleeder looks like, have to loosen the cap to get water out. The first time I loosen up that thing the water started shooting out and I went nuts, couldn't figure out how to close it and water wont stop gushing out. I couldn't able to find a plier or see the tiny hole on the cap. I thought the cap was cracked but there was a tiny hole. The other bleeders requires a key forgot to take pictures.

 

Last edited by NJT; 02-24-13 at 07:25 PM.
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Old 02-24-13, 03:12 PM
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I will be shopping around for taco powerhead.. Thinking about buying 1 blue and 2 of the other ones. Not sure why one of them is green.
 
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Old 02-24-13, 07:01 PM
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Ok... where to start... lessee here...

First thing that I was curious about is the expansion tank piping... how is that connected into the system? Is there a simple TEE fitting that it's screwed into? There is a valve on the pipe next to it that is closed. What is that valve for?

Is there an air scoop anywhere on the system? Are there any automatic air vents anywhere?

I presume that the circulator pump is down at the bottom of the boiler on the right side?

Where is the water fill valve?

I do not believe that the 24VAC transformer on the wall is of sufficient capacity to run 6 zone valves, and this could be part or all of the reason that you are thinking that a couple of the valves are not operating. If the transformer is too small, the voltage may 'sag' enough when all six are trying to open to prevent them from doing so.

You could in fact have a bad zone valve or two, but I believe you need a bigger transformer.

There should not be more than THREE valves being powered from a 40 VA transformer.

Next time you are there, see if there are any labels or ratings on the transformer.

Do you own a multimeter and know how to use it?

=============================

I don't know what you mean by "...1 blue and 2 of the other ones...".

Presuming that all the valves are the same ( 571-2 ) this is the correct head:

555-050RP - Taco 555-050RP - Zone Valve Power Head (Series 570)

Go ahead and pick up replacements if you like, but I would first be certain that you have enough transformer installed, and would do some checking to determine the actual problem before throwing money at it.

Is there a way to replace the Taco valve without plumbing??
Yes, the power head is easily replaced. LABEL the wires and remove them. Slightly push down and turn the head clockwise and it will pop off. Replacement is the reverse.

See: http://www.taco-hvac.com/uploads/Fil...ry/102-076.pdf
 
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Old 02-25-13, 11:18 AM
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I noticed that too. This setup is different from every one I've seen online.
First thing that I was curious about is the expansion tank piping... how is that connected into the system? Is there a simple TEE fitting that it's screwed into? There is a valve on the pipe next to it that is closed. What is that valve for?
The valve you see attached before the expansion tank, it feeds cold water into the system aka water fill valve. On top of the tank there is only a TEE fitting screwed onto it.

Is there an air scoop anywhere on the system? Are there any automatic air vents anywhere?I presume that the circulator pump is down at the bottom of the boiler on the right side?
I did not see an air scoop or auto air vent, I need to check again next week. The circulater ump is on the right side (pump attached to the water return piping?).


And there is a Big transformer box on the corner didnt take a picture of it, that is where the power is or some of the wires are coming from.

--------

After digging more into this, I have concluded that the culprit is the 2 bad zone valves in the first floor. We had the house for 2 years now and always left the temp set at 55F in the first floor and never had problem (at least that is what the previous owner told us to do). This past weekend, I set it to 75F and Temp never raised. Going to grab those Taco PowerHEads from HDepot.

As for the water noise, I am afraid to think it might be trapped in the 2 Zones that are not working. Will find out next week.

THANKS A BUNCH NJ TROOPER for the tips!!!
 
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Old 02-25-13, 04:44 PM
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While this piping job LOOKS neat and well thought out, it was obviously done by someone who did not have a lot of experience piping hot water heating systems.

The expansion tank is all wrong, there is no provision for venting air, etc....

You will have constant problems with air in this system because of this.

And there is a Big transformer box on the corner didnt take a picture of it, that is where the power is or some of the wires are coming from.
Right, that's your 'aquastat'. It's the control that regulates the boiler temperature and turns the pump on and off. I'm quite certain that it is not powering your zone valves.

It could very well be that your zone valves are NOT bad. If you open all six of those zones at once, it is highly likely that the small transformer will become blazing hot to the touch and the voltage output will sag to the point that it is not capable of opening all six at once.

You need to do one of two things...

Either ADD a SECOND transformer and rewire the zone valves so that there are THREE each on ONE transformer...

OR

Find a SINGLE transformer of 80 VA rating or higher to power all six of the valves.

A 75VA transformer will work:


image courtesy pexsupply.com

AT175A1008 - Honeywell AT175A1008 - Foot mounted 120/208/240 Vac Transformer w/ 9 in. Lead Wires (75VA)

This is a GIVEN if that existing transformer is only a 40 VA part. But we do not yet know that it IS only a 40VA part...

One test that you can do:

Turn the thermostats up ONE AT A TIME and see if the respective zone valve opens and the boiler fires and heats the zone individually. With only ONE valve at a time open, the transformer should be capable of operating properly.

Your problem with the air in the system is secondary to this. If that transformer gives up, you will have NO heat at all...
 

Last edited by NJT; 02-25-13 at 05:02 PM.
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Old 03-04-13, 06:58 AM
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UPDATES: Out of the the last 2 bad zones, 1 was fixed by simply replacing the taco powerhead, the other zone will not work even when set to manual.

Here is a photo of the right side of the boiler.



Is this the aquastat??


What is this thing, wires from this thing are routed to the thermostat and taco valves.




This powerhead happen to be bad. Simply replacing it with a new one fixed this zone. At first I was concerned because it was different from the other ones.




Still don't understand how the Taco Powerhead open the valves.



I am down to one last zone and it seems to be the hardest one so far.

Replacing the powerhead did not help at all. I tried to manually open the valve by moving the lever down from Auto to Open and water will not flow. I left the middle wire attached when moving the lever to open.

Time for soldering?? If that is the case I will wait for summer.
 
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Old 03-04-13, 12:10 PM
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Is this the aquastat??
No, without a better pic I can only guess and say that is your TRANSFORMER, and it appears to be a large enough one to power all the valves. Is there any labeling on it?

And I believe the thing on the wall above the bricks, that I thought was your transformer, is actually the RELAY that is shown in the pic below where you asked "What is this thing, wires from this thing are routed to the thermostat and taco valves"

Your aquastat is the gray box on the side of the boiler in the pic of the right side of the boiler.

Still don't understand how the Taco Powerhead open the valves.
When 24VAC power is applied between terminals 1 & 2 it activates a 'HEAT MOTOR', which is a heating element surrounding a 'wax capsule bellows' mechanism. When the wax inside the capsule is heated, it expands and pushes on that 'button' and opens the valve. Also, when the valve opens, it operates a switch which is connected to terminals 2 & 3. When that switch is operated, it signals the boiler to fire up.

There is a good explanation how they work in this PDF:

http://www.taco-hvac.com/track_file....nload_id=10693

Time for soldering?? If that is the case I will wait for summer.
Have I asked if you own and know how to use a multimeter? If so, that's where I would go next.

Determine if the thermostat is telling the zone valve to open by measuring the voltage at 1 & 2, then to see if the valve is opening by measuring 2 & 3 ...

It is possible that no water is flowing because of air blockage also... maybe the valve IS opening.
 

Last edited by NJT; 03-04-13 at 03:03 PM.
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Old 03-25-13, 07:46 AM
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Sorry it took so long. I finally had the chance to go up there and did the test with a multimeter.

There is voltage on terminal 1 and 2 when thermostat is on and voltage on 2 and 3 when off.

But when I unplug terminal 1 and 2 to check continuity there is no readings.

so this could be the transformer? but everyother zone is working or is it the other half of the valve?
 
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Old 03-25-13, 09:39 AM
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No, I don't think the transformer. If it was the transformer you would not have any voltage on 1 & 2 when the thermostat called for heat.

Voltage at 1 & 2 is telling us that the thermostat and transformer are working properly.

Voltage at 2 & 3 when the valve is CLOSED or OFF is also correct. This voltage should go away when the valve is OPEN or ON.

Everything here is showing that the valve is opening.

I'm still of the opinion that you have an air blockage in the zone.
 
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Old 03-25-13, 10:30 AM
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If that is the case. I was going to try turning off the thermostat in every zone to keep the close. Then turn on thermostat on the bad zone only and raise the PSI to let it sit for while to see what it does.
 
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