TACO Actuator EN024Q4A2 Replacement

Reply

  #1  
Old 12-09-10, 07:56 PM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
TACO Actuator EN024Q4A2 Replacement

Say, I have two zones. Flow to both zones is controlled by Taco EN024Q4A2 isolation valves. I get 24v from the thermostat to the taco valve and the taco valve repositions open very nicely; however, the taco does not send 24 volts to the aquastat to tell the circulator to run, so the circulator does not run. So I wonder where does a guy get a taco EN024Q4A2 controller?
 
Sponsored Links
  #2  
Old 12-09-10, 08:38 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
So I wonder where does a guy get a taco EN024Q4A2 controller?
Pex Supply ?

EN024Q4A2 - Taco EN024Q4A2 - QA Actuator For EBV Valves

Make sure you've done all the troubleshooting before dropping $75 on a new head though.

http://s3.pexsupply.com/manuals/1258..._PROD_FILE.pdf

Note that the head doesn't actually 'send 24 volts' to the aquastat. The valve head only provides a 'contact closure' that completes the circuit and triggers the aquastat.
 
  #3  
Old 12-10-10, 04:56 AM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
Thanks for the link to pex. So I would like to continue troubleshooting, but do not know the next step. I have 24v coming into the taco controller with the thermostat ordering heat, but I have 0 volts coming out of that taco controller. Is there a way to pop the controller open to actually inspect or check the end switch?
 
  #4  
Old 12-10-10, 11:01 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
When you say 'controller' I want to make sure that I understand that you mean ZONE VALVE POWER HEAD... or VALVE ACTUATOR ... controller is too ambiguous.

When the valves are OPEN, the ENDSWITCH should be CLOSED.

Are the endswitches of your valves wired as shown in the PDF file diagram, in parallel and then on to the T T terminals of an aquastat?

If so, put your meter set for AC volts on the T T terminals of the aquastat.

With NO CALL for heat from any valve, you should see appx 24VAC.

Turn each zone thermostat one at a time to max... that valve should open, and when it does, if the endswitch in that valve is closing, the voltage on T T terminals should go to ZERO. You should hear the relay in the aquastat 'click' and the boiler should fire, the circulator should run ... then turn the t'stat back down, and continue to the next zone... do this for each zone ... if you don't see a change when the valve opens, either the endswitch is bad, or there's a loose connection in the wiring, or the valve itself is not opening.
 
  #5  
Old 12-10-10, 11:08 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
In re-reading your posts, I'm still a little unclear about the exact problem.

Do BOTH of your two zones act the same way? NEITHER one will start the boiler?

What boiler make/model, with what aquastat model?

If you do not see 24V on the T T terminals of the aquastat at any time, then the problem could be there, and not with the zone valves.
 
  #6  
Old 12-10-10, 08:13 PM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
28v

ok. so I remove the call for heat from both thermostats and i watch both taco valves roll shut. then I measure the T T terminals on the honeywell L8124A-1007 Aquastat and find 28v AC. Then I insert a call for heat from the thermostat and I watch the taco valve roll open and measure 0 volts at the T T terminals on the honeywell L8124A-1007 Aquastat -- but 0 volts on the c1 c2 terminals that would power up the circulator pump. Does that indicate the taco valve power head is broiken?
 
  #7  
Old 12-10-10, 10:18 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
No, you SHOULD see appx 24VAC on the TT terminals when there is NO heat call, and ZERO when there is a heat call.

Do BOTH of the zone valves do the same thing?

When the zone valves OPEN, do you hear the relay in the 8124 aquastat 'click' ?

What are the settings on the three dials in the 8124 ?
 
  #8  
Old 12-11-10, 03:45 AM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
settings are : DIFF 15 LO 150 HI 190 working on the rest of the questions.
 
  #9  
Old 12-11-10, 03:58 AM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
ok. so when the taco valve moves from open to shut I can see the relay in the L8124 reposition and I can measure the voltage between T T as 0v when the taco is full open and 28v when the taco is closed.
 
  #10  
Old 12-11-10, 09:35 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Aquastat settings are fine... reason I asked is because you never want the LOW any closer than 20 degrees from the high, because that can whack out the circulator operation.

It sounds to me that your zone valves are working fine, and if the relay pulls in on the 8124 and there is still no voltage at C1 C2, there is a problem with the aquastat.

By the way, when we say 24VAC, that is the 'nominal' voltage. 28 VAC is to be considered normal.
 
  #11  
Old 12-11-10, 09:41 AM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
aquastat

ok. My local home depot does not carry the L8124a-1007, but I see one on ebay. Is that going to be really hard to install, or not so bad for an average guy?
Alos, is ther a reason I should be seeking the exact model L8124a-1007 for my replacement instead of the l8124c-1003 which I also see on ebay?
Thanks.
 
  #12  
Old 12-11-10, 09:55 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
This is on an oil fired system, correct?

It's not difficult... just make sure that you tag the wires before removing...

You might first want to take a close look at the relay contacts to make sure they are clean and that a spider hasn't gotten stuck between them. With a bright flashlight, and a magnifying glass if you need one (I DO!) FIRST turn the power to the boiler off and take a close look at the relay in the 8124. See if you can identify the part that makes the contact. There are TWO sets of contacts, one for the burner, and one for the circulator.

Take a piece of shirt cardboard or a matchbook cover... cut a strip that will fit between the contacts. Saturate it with rubbing alcohol. Slide it between the contacts and carefully with your finger push the contacts closed. Slide the cardboard between the contacts and see if simply cleaning them will get you out of the woods for now...

more about the replacements in a bit...
 
  #13  
Old 12-11-10, 09:57 AM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
yes I am oil. going to try the contact trick right now.
 
  #14  
Old 12-11-10, 10:03 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Check out Figure 2 in this PDF file. It shows how the aquastat is attached to the immersion well in the boiler.

The A and the C are nearly identical... if not exactly identical... Honeywell doesn't make it easy to determine the differences... both will work...

But, take a look also at the L7224U universal replacement:

Honeywell L7224U product page

Available here:

PexSupply - Honeywell L7224U1002 - 120 Vac Oil Electronic Aquastat

I would be EXTREMELY careful about ebay purchases... unless it is from a reputable seller. (Patriot Supply maintains a store there...) I would most definitely NOT purchase anything that was 'used'.
 
  #15  
Old 12-11-10, 10:09 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
The 'A' model is a vertical mount, the 'C' model is horizontal... that's the only difference that I can see.

Aside from the position of the clamp screw, they are interchangeable. The specs are the same.
 
  #16  
Old 12-11-10, 11:02 AM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
ok. Thanks. I tried the alcohol cleaning trick. No spiders. Still 0v at C1 and C2. Thanks for the tip on Patriot Supply. I found them on ebay. They have an Aquastat HONEYWELL L8124A1015---but no 1007. I will order taht one from Patriot, but I cannot tell if that 1015 is a different set up than my 1007. Do you havve any experience with that?
 
  #17  
Old 12-11-10, 11:29 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Here's where ya need to be real careful...

Comparing the 1007 to 1015

The only difference that I can see here is the INSULATION DEPTH... I don't know if that means that the bulb itself is longer or not... you might order that one only to find that your immersion well is not deep enough...

Although, looking at Honey's CATALOG, it says that the 1007 INCLUDES a 3" insertion well... so like I said, figuring out Honey's various 'flavors' is next to impossible most times.

Are you shying away from the L7224U for a reason?
 
  #18  
Old 12-11-10, 01:04 PM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
I am afraid the L7224u will be too different from my L8124A-1007 to allow re-use of the bulb that goes into the boiler--and I was hoping t not have to drain the boiler to do the swap. Plus, after reading the honey web site on L7224u, it seems as though the L7224u does not come with the entire set of parts I'll need and I am apprehensive about not knowing all of the pieces I should order---so the L8124A-1007 seems like the less risky move for me. Am I thinking of it wrong?
 
  #19  
Old 12-11-10, 02:20 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Am I thinking of it wrong?
I think so... the bulb on the old aquastat is not used... you don't re-use the old one. The existing immersion well is suitable for the new aquastat. It comes with an electronic sensor that goes into the existing well.

You don't have to drain the boiler.

it seems as though the L7224u does not come with the entire set of parts I'll need
It does... the other stuff that you see are OPTIONS. Outdoor reset, etc.

The only real caveat may be that the wiring on your existing unit may come up a little short, but I doubt it.

Maybe "Zoesdad" will chime in here, as he recently installed one to replace an 8124 ... or was it an 8148 ... whatever...

But, if you feel more comfortable going with an exact replacement, there's absolutely nothing wrong with that! I wuz just wonderin'...

Whatever you order, check the various places for price... Patriot also has a regular website, you don't have to buy through ebay, and prices are about the same. Patriot Supply - Industrial, Commercial & Residential HVAC Parts & Equipment

Compare prices to:
PEX - Radiant Heat - Radiant Heating - Plumbing Supplies - PexSupply.com

By the way, if you get in a real bind for heat while you are waiting for the replacement, you can wire a cord directly to the circulator and plug it in the wall.
 
  #20  
Old 12-11-10, 02:29 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
By the way... the Beckett 7600 'aquasmart' unit will also work:

Patriot Supply - 7600A0001U
 
  #21  
Old 12-11-10, 05:16 PM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
okay. SO I hot-wired the circulator pump which worked great--and I just babysat it while the house got warm, then when the taco valves went I pulled the plug on it. I also used the link you gave me and found the L8124A-1007 at the pex site--ordered it there for $167 delivered. I think I may come back to this thread when my box arrives. Thanks for the advice.
 
  #22  
Old 12-11-10, 05:27 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
That's the ticket!

You are right about having to babysit... because you don't want the pump running into closed valves.

We'll be here when yer ready...
 
  #23  
Old 12-14-10, 06:49 PM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
ready

okay...so the parts came in the mail today. I am ready to go. I would love to have an estimate of how long the job should take--to swap out an old L8124A-1007 for a brand new one. Any one have a rough idea of that?
 
  #24  
Old 12-14-10, 07:33 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
I think an experienced guy could probably do in like a half hour or so... homeowner DIY, an hour or two? You've got like 6 wire connections, the clamp that holds the 'stat to the well, slide out, slide back in... hook up wires...
 
  #25  
Old 12-14-10, 08:09 PM
Member
Thread Starter
Join Date: Nov 2010
Location: USA
Posts: 18
Received 0 Votes on 0 Posts
You are correct Sir!

45 minutes including retests.
You gave me the confidence to do the repair.
Thanks.
The instructions from honeywell (for a first timer) sure made is sound like I would have to drain the boiler---which I could not understand when I looked at the boiler---but that is what the paper instruction from h-well said. When you said no--I went for it.
Done in 45 minutes.
Blowing hot all over the house. Both t-stats calling for and getting heat. You are the man.

Thansk again.
 
  #26  
Old 12-14-10, 08:20 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
I know what you mean about the directions... I think you got a new immersion well with the a'stat, right? I think those instructions are geared toward replacing the well also, which is rarely necessary!

Great! we like warm! No, YOU THE MAN!
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: