Help Needed w/Two Zone Valves and DHW Wiring

Reply

  #1  
Old 02-19-20, 07:15 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Help Needed w/Two Zone Valves and DHW Wiring

My old Burnham tankless boiler gave up the ghost and puked water eveywhere. I purchased a 'new to me' Weil Mcclain boiler and indirect water heater. I also purchased a Taco 3 Zone control panel but I purchased the wrong one. I purchased a switch relay (SR503) panel instead of a zone valve control (ZVC404). This just made matters worse because I am not familiar with 24V wiring.

Anyway, below is what I am working with:

(2) Honeywell 4 Wire Zones #V8034F
(1) WM DHW Aqua Plus 45
(1) WM Boiler CGA-4-SPDN
(1) Taco Switch Relay SR503 EXP-4

I currently have all of the plumbing done. The gas valve pilot is on and lit after cleaning the pilot and thermocouple. As you may have guessed, I have a standing pilot. I also completed the 120V wiring to the Taco switch relay, the green indicator light is on in the panel. 120V is ran from the main box to the junction box on the side of the boiler.

I desperately need help with the 24V wiring. My thermostats are digital. So I guess if some can start with the red and white TT wiring coming out of the main power box, it would be greatly appreciated.
 
Sponsored Links
  #2  
Old 02-19-20, 05:47 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 55,114
Received 585 Votes on 551 Posts
Welcome to the forums.

How many heating zones do you have ?
You need a zone valve for each heating zone.
You need a zone valve for your storage tank.

The SR503 switches 120vAC to circulator pumps and is of no use here.
You need a 403/404.

I can help you wire without a zone controller but you won't have DHW priority.
You could temporarily wire now and get a zone valve controller.
 
  #3  
Old 02-19-20, 07:35 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Thanks for the quick response PJmax.

I only have two zones, upstairs and downstairs. I will be adding a third zone for the DHW.

I am definitely going to uninstall and return the SR503. That was my 100% my error.

For the DHW, I originally had the storage tank wired to a Honeywell RA832A box. When I turned the dial on the storage tank to a warmer temperature, the flapper in the Honeywell box would click and the primary circulator pump would run. The gas valve would not turn on because of it not being wired correctly but fundamentally, it seemed to function properly.

If I can reinstall the Honeywell box for the DHW, would this mean I would not have to solder in another zone valve? If I have to solder in another zone valve, I have two extra Honeywell V8043E1012. Will these do?

Also, if I can use the Honeywell box, I will only have two zones remaining to wire up. Let me know if I can wire up the two zones without a controller for now.

Thanks.
 
  #4  
Old 02-19-20, 07:45 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 55,114
Received 585 Votes on 551 Posts
If you only have one circulator..... then the HW tank needs a zone valve too.

 
  #5  
Old 02-19-20, 09:33 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
I have two separate circulators, one for the two zones (upstairs and downstairs) and one for the indirect water heater.
 
  #6  
Old 02-20-20, 07:16 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 55,114
Received 585 Votes on 551 Posts
How does that work ?
I'm used to one circulator running everything or each zone and the DHW has a circulator.

Typically any call for heat will open the correct zone valve and start the circulator.

You may be better off with the 503 as you need some way to control the circulators.
We could have the stat open the zone valve...... then the end switch from the zone valve activates the 503.
 
  #7  
Old 02-21-20, 04:49 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
I have returned the SR503 and purchased the ZVC403. At least this way, I will have the proper controller. The only thing with the ZVC403 is the wiring for the circulator pumps. The wiring diahram shows the ability to run three pumps but the wiring looks like spaghetti to me. So I may need help when that part comes.

Yes, the problem with using the Honeywell RA832A box to control the DHW heater is there is no 24V signal coming from the box to the furnace to activate the burner. Then for the zone valves, I had no way to activate the circulator for that zone (I have radiant floor heat downstairs and baseboards upstairs). So at that point, I figure it was easier to buy a controller to send the proper signals.

I am going from a tankless water heater boiler system that had an aquastat and on demand pilot to a boiler with a DHW tank, standing pilot, a third zone and no aquastat. I hope this helps explain why I am so confused. LOL!!!
 
  #8  
Old 02-21-20, 06:21 AM
C
Member
Join Date: Mar 2007
Posts: 1,593
Received 31 Votes on 28 Posts
Deleted - I posted my question in the wrong thread. It was not my intention to hijack the thread. Sorry.
 

Last edited by cwbuff; 02-21-20 at 09:19 AM.
  #9  
Old 02-21-20, 07:45 AM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Location: USA
Posts: 4,212
Received 25 Votes on 24 Posts
Hi, take this one step at a time, mount the control, run the 120 volt supply to it, take a breath, connect up conductors for boiler control, next connect thermostat conductors to proper terminals, connect up conductors from zone valves,
circulator will be controlled from the aquastat on the boiler.
I just noticed you said you had 2 circulators, I think your best would be to install a new valve for the DHW could go onto the priority zone, and only have 1 circulator, but I am not the plumber.
Have fun!
Geo
 

Last edited by Geochurchi; 02-21-20 at 08:09 AM.
  #10  
Old 02-21-20, 07:51 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 55,114
Received 585 Votes on 551 Posts
two circulator pumps instead of one pump and two zone valves.
I'm not the boiler specialist but if two zone valves are used.... there should be one pump.
If two pumps were used there would be no reason for any zone valves.
 
  #11  
Old 02-21-20, 10:43 AM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,859
Received 35 Votes on 33 Posts
This may be a little late but your Taco 503 would have worked for you.

What you could have done is to bring each heating zone valve end switch wiring as PJ mentioned into the TT terminals on Z1 & Z2 and put your heating pump on Zone 1 and then install a jumper between Z1 & Z2 pump terminals so that when either zone called the pump would run to deliver heat to the zone calling for heat so you still have 2 independent zones turning on 1 pump.

Your indirect HWH will get connected to Z3 and put on priority and your HWH pump would get tied into your Z3 pump terminals.

Your ZVC will work also with 2 pumps by following your alternate wiring diagram at the bottom left of the schematic. Just a side note. You have Honeywell 4 wire ZV's so you follow the alternate wiring diagram on the right side of the schematic. The 2 YELLOW wires go on 1 & 2 and the 2 RED go on 3 & 4.

Hope this helps a little.
 
  #12  
Old 02-21-20, 03:00 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Geochurchi "circulator will be controlled from the aquastat on the boiler."

My boiler does not have an aquastat. My old Burnham tankless water heater did.
 
  #13  
Old 02-21-20, 03:27 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Spott "This may be a little late but your Taco 503 would have worked for you."

Yeah, just a hair too late. The SR503 is going back tomorrow. The ZVC403 is already on its way.

I'll pay close attention to the schematics on the lower left for the ZVC503. I have the older Honeywell zones soldered in. They have the TH/TR on top with the end switch. The extra Honeywell zones I have sitting on the shelf have the yellow and red wires. I am not sure if I have to solder in a third zone for the DHW. The way I have it plumbed, the water will just circulate from the boiler to the indirect water heater when hot water is needed. I honestly do not know what a zone valve does beyond opening and closing to allow water to flow. If the end switch sends or receives a signal to stop the process, then I guess I have to install a zone valve for the DHW.

 
  #14  
Old 02-21-20, 04:39 PM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Location: USA
Posts: 4,212
Received 25 Votes on 24 Posts
Interesting, how is the boiler controlled? the zone valve for the DHW would be controlled by the aquastat on the DHW, unless I am missing something, can you post some pics of the boiler?
Geo
 
  #15  
Old 02-21-20, 05:42 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,859
Received 35 Votes on 33 Posts
When you say you plumed the DHW tank with a pipe from the boiler I'm assuming you met you came off the supply line of the boiler and came back from the tank into the return line of the boiler. If you want to use the additional pump for the DHW you install it on either on the supply or return of the boiler. Now it is important to know that if you use the pump you must install a flocheck to stop the water from flowing to the tank when the heating zones call. If you put the pump on the supply side you install the pump and then after the pump install the flocheck so the flow from the pump will open the FC allowing water to circulate through the zone and only that zone. Below is the FC you will need assuming you are using 3/4" pipe to the tank.

https://www.supplyhouse.com/Taco-219-4-3-4-CxC-Horizontal-Bronze-Taco-Flo-Chek.

You do not need FC's with zone valves because when they are closed they are positive shutoffs and will not allow heated water to flow to unwanted zones.

Now the TH & TR on your ZV's. TH is your power terminal so TH will go to 1, TR= 2, END SWITCH goes to 3 & 4. If you didn't have the panel and were just using a 40VA 24V transformer it would just be a series circuit to wires these in. Starting with the transformer to the red term on the stat, then from the white term on stat to TH on the ZV, then from TH back to the transformer. That circuit would open the ZV and the your END SWITCH terminals would go back to TT in your boiler control to start the pump and burner to heat the water.

That Taco Relay panel is doing all of that with just tying your ZV's 4 wires into their proper terminals so it's a lot easier and cleaner as far as wiring goes.

If it sounds confusing pics of your piping would be helpful to see what you have done if possible.
 
  #16  
Old 02-22-20, 08:35 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Geochurchi, my boiler is like this one except mine is 110K BTU and has a standing pilot. Model # CGA4-SPDN. Inside the boiler is a fan switch center. I assume these collection of transformers are doing all the work.

https://www.supplyhouse.com/Weil-Mcl...nition-Nat-Gas


 

Last edited by Kenpachi; 02-22-20 at 09:04 AM.
  #17  
Old 02-22-20, 09:03 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Spott,
Yes, I have the circulator for the DHW installed on the supply side and is piped exactly as you described. However, I do not have a zone valve or flow check installed after the circulator. Your explanation as to why I need one or the other makes sense. I will install one the extra zone valves I have on the shelf. Also thanks for explaining how to install both types of 4 wire zones. I will have everything ready so when the ZVC403 arrives I can plug everything in. The last known problem I have now is my Field Control damper. I fried it before I found the wiring and troubleshooting diagram. So for now, I manually have the damper open.
 
  #18  
Old 02-22-20, 11:31 AM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,859
Received 35 Votes on 33 Posts
K,
If you have the pump installed you need the FC and not the ZV. If you install the ZV you will have to wire it in and with the ZVC 403 you have no room.

That control is made for 3 zones. You have 2 heating zones and your DHW tank aquastat which is all the room you have.

At this point because you got the 3 zone instead of the 4 as a spare in case of system expansion the only thing you can do is add your FC. If you use the set of terminals to wire in thye ZV you will have no way to turn on your DHW tank. Those terminals can be used for either the ZV or the tank aquastat but not both.



 
  #19  
Old 02-22-20, 12:51 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Spott,

My DHW heater does not have an aquastat. It just has two wires (R/W) coming out of the unit near the tempature control valve. I assumed this is similar to a thermostat. Unless I need an aquastat (not sure where it would go), I only have three zones; upstairs, downstairs and the DHW tank. I have a Honeywell RA832A box but 24v does not come out of any auxiliary locations when I had it hooked up before to the DHW.
 
  #20  
Old 02-22-20, 01:05 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,859
Received 35 Votes on 33 Posts
K,
Those 2 wires for your temp control is what I meant by aquastat. you do not have to add anything. Sorry for the confusion. Those wires will go where the other stat terminals go and will activate the pump and burner needed.

Try not to overthink this. Just add that FC and you will be fine.
 
  #21  
Old 02-23-20, 12:36 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Spott,

No worries my friend. I appreciate everyone trying help me. I ordered the Taco FC today. Should be here by Tuesday. I should have the ZVC403 by Tuesday as well. I will keep everyone posted.

Thanks again.
 
  #22  
Old 02-23-20, 02:38 PM
P
Member
Join Date: Feb 2019
Location: United States
Posts: 68
Received 0 Votes on 0 Posts
I can't read through all the posts right now but it might help if you take a look at a post I made back in Feb 2019. I rewired my system and installed a SR503 panel, which is detailed in that post. With my system, I have four zones but only three circulators. Two of the zones share a circulator and are separated by two taco 3-wire zone valves. The end switches on the two zone valves close when there is a call for heat; these switches wire to the zone three's RW on the SR panel; thus either zone valve calling for heat will activate the same (shared) circulator. The trick with mine was installing a separate transformer to power the zone valves. Your valves are different but my guess is they require power at terminals 1-2, which also wire to your thermostat, and 3-4 are an end switch that can go to the SR panel RW.

If you look at my post; the schematic for option 3 was what I installed. Its been working well ever since.

The post is here
 
  #23  
Old 02-24-20, 09:13 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
PBCT2019:
The SR503 I had was returned. The ZVC403 is scheduled to arrive tomorrow. Whay you say about the extra transformer makes sense because mounted on the top of the boiler I purchased was s Honeywell R8222D transformer with a myriad of red and white wires attached to it. I remember thinking I do not know what this transformer does but I am not dealing with it. So I removed it and placed the transformer in the parts bin. LOL.
 
  #24  
Old 02-25-20, 05:03 AM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Location: USA
Posts: 4,212
Received 25 Votes on 24 Posts
Hi, you shouldn’t need additional transformers, the ZCV 403, will supply what you need.
Geo
 
  #25  
Old 02-25-20, 06:43 AM
P
Member
Join Date: Feb 2019
Location: United States
Posts: 68
Received 0 Votes on 0 Posts
Geochurchi is correct; the ZVC panel will power your zone valves, the SR won't and thus requires additional transformers for the valves. Taco has done a great job making really easy plug n play controllers. The problem is if people have a hybrid system, it takes a little extra design to set up. By hybrid I mean a mixture of a circulator designed system (each zone has a circ and no zone valves) or a zone valve system (the whole system has one circ but zone valves direct flow to areas calling for heat). I currently have 4 zones but 3 circs; zones 3 and 4 are split but valves but share a circ. I opted to using an SR panel and then power my zone valves separately, however, there are various other configurations that would work.

So first, sorry if anything I mention is covered above, I have fallen behind in the post and its a struggle to catch up.

I think your solution is right there in ZVC wiring diagram . Sorry if this was already discussed above and shot down!

https://s3.amazonaws.com/s3.supplyho...%20Install.pdf

See the wiring diagram in the link above. On page 1, half way down on the left hand side is a small box "Optional System and/or DHW and/or Secondary Circulators". Wire your circulators exactly like that. Next the larger diagram on that same page, will show you how to connect your thermostats (at the top of the diagram) and the zone valves (at the bottom, just make sure you follow instructions for your 4 wire valves). Then run XX form the ZVC to TT on your boiler controller. It all should be pretty simple plug n play after sorting out the circulator hook up.
 
  #26  
Old 02-25-20, 08:17 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
The zone controller and the flow check valve arrived today but I am stuck on the circulator pump wiring. The zone controller I purchased is the ZVC403. Not the ZVC403-4, just the plain ZVC403. The wiring diagrams are similar but slightly different. I cannot figure out how to connect two circulator pumps and send a signal to the boiler to activate the gas valve. I think I purchased the wrong zone controller again. This one looks like it is only meant for one circulation pump.
 
  #27  
Old 02-25-20, 08:34 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Hold a sec...I currently have the boiler receiving 120V power directly from the main outlet to the junction box on side of the boiler. Now that i have a zone controller, does this mean 120V power will now come from the control box? I see a hot and neutral in the diagram coming from the normally open, normally closed and common box where the pumps are connected.
 
  #28  
Old 02-26-20, 08:56 AM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Location: USA
Posts: 4,212
Received 25 Votes on 24 Posts
Zone valves

ZCV can be fed from the same feed that the boiler control is supplied from, how many circulators do you have? One circ. should be supplied as it was originally.
TT terminals on ZVC will parallel with thermostat terminals in the boiler control.

Geo
 
  #29  
Old 02-26-20, 09:07 AM
P
Member
Join Date: Feb 2019
Location: United States
Posts: 68
Received 0 Votes on 0 Posts
hmm.. ZVC403 but not -4? Maybe you have an older edition of that 403?? Can you send a picture of the board terminals and also a picture of the wire diagram it came with? I want to make sure we are looking at the same model.

The diagram I sent above is designed to support a second circ with priority for DHW. maybe your model doesn't support that? If it doesn't, I would probably return for a different panel. But first, lets figure out exactly what you have before we decide to return and replace.

Regarding the power:
120v volt should some into the ZVC from your kill switch for the boiler power feed. It will provide 120V power for your circulators (at the pump end switch) and 24VAC power for your zone valves and your thermostats via the transformer installed in the panel.

For firing the boiler
This board will not send a line voltage signal to fire the boiler. The only way it can fire the boiler is via the "X"X" isolated end switch. This end switch is typically wired to TT terminals on your boiler controller. The XX is dry and simply closes the charged circuit at TT on the boiler. This switch is really no different than the switch that closes in your thermostat when it calls for heat.

For powering the circs.
All pumps share a neutral line. HOT line comes into the pump end switch X. A call for heat from any zone closes the pump end switch and energizes the system pump and the "com" terminal. If zone three (your priority and DHW) calls for heat, the "n/o" switch closes and your DHW pump becomes active. Where things get hairy and you may need to call Taco to confirm, is I dont see what kills the system pump when priority zone three gets heat. I believe this wiring configuration is for a scenario where the system pump must always be on.

Alternatively, what you can do (assuming you have the end switch terminals) on your panel:
Both circs share a neutral. Line voltage into "X" on pump end switch. Output "X" on that end switch goes to "Com" on the zone 3 end switch. The heat circulator wires to the "N/C" terminal on the zone 3 end switch. The DHW circulator is wire to the "N/O" on the zone 3 end switch.

So, any zone calls for heat, XX end switch closes and sends 120V to "COM". The "N/C" circuit forwards this 120V to the heating circulator. If the zone calling for heat is DHW and your priority switch is on on the panel, then the "N/O" circuit closes, energizing the DHW circ and the "N/C" circuit opens, stopping the heating circ, thus giving priority to DHW.


All this is moot until we know what board you have though. Lets figure that out and then we can decide if this board will work, if you need a second board, or if you should replace with a different board.
 

Last edited by pbct2019; 02-26-20 at 09:31 AM.
  #30  
Old 02-26-20, 09:27 AM
P
Member
Join Date: Feb 2019
Location: United States
Posts: 68
Received 0 Votes on 0 Posts
I guess to be concise and make sure we have all the details.. Please confirm the following:

1) you have two circulators in parallel (i think your boiler comes factory with one directly on top)
2) photos of wiring diagrams that are on your boiler (specifically for the controller on the inside).. the manual doesn't seem to include them.
2) you want DHW priority. ie if indirect tank calls for heat, your heating zone circulators shut off
3) exactly which ZVC panel you have. please upload photos of board and wiring diagram please
4) any legacy relays you still have laying around. I believe you mentioned a honeywell?

There is a definitely an easy to do solution in front of us, we just need to confirm the hardware to make the best choice.
 
  #31  
Old 02-26-20, 11:19 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
I do not have an account to host images. I will see what I can do to help this process. I was able to find a wiring diagram for the ZVC403 I have. It is on this website in another discussion.

https://www.doityourself.com/forum/t...hermostat.html

 
  #32  
Old 02-26-20, 11:27 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
I have two circulator pumps; one on the return side for the zone valves and another on the supply side for the DHW. Neither of the pumps are wired at this time. I can run them parallel once things are figured out.
 
  #33  
Old 02-26-20, 11:38 AM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
When you Google 'weil mcclain gold cga boiler manual' the first manual is what I am using. It has a black and white cover page. It has 68 pages and 15K in size. Once open, go to page 34 of 68. That schematic matches the color wiring in my boiler exactly; even the standing pilot part.
 
  #34  
Old 02-26-20, 03:24 PM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Location: USA
Posts: 4,212
Received 25 Votes on 24 Posts
Just curious, why not 1 circulator and 3 zone valves ?
Geo
 
  #35  
Old 02-26-20, 03:37 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Geochurchi
I was advised by a family member that I needed another pump for the DHW. So I installed a 2nd pump. I have no other logic to support this install.
Technically, I do not have a 'traditional' 3rd zone valve. The ZV controlling the DHW tank is built in.
 

Last edited by Kenpachi; 02-26-20 at 03:59 PM.
  #36  
Old 02-26-20, 04:39 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,859
Received 35 Votes on 33 Posts
I understand your pump is installed but in place of the pump you could have installed a zone valve and one pump for all 3 zones would have worked and you could have still had your tank on priority. If it eases the pain at all, in my opinion you are better off with the pump. You get better flow than with a zone valve. The tank co. used to recommend pumps over ZV's but now I think they gave up just to sell tanks.

I have an Amtrol Boilermate and it actually comes with a pump.
 
  #37  
Old 02-26-20, 05:04 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Hey Spott,

That does ease the pain some. I do not feel like uninstalling the 2nd pump, especially after I spent $50 bucks on a flow check valve.

I think they way P-2019 explained how to wire the circulators is the way to go. However my zone controller does not have an extra isolated end switch to send power to boiler TT. I just have the end switch and N/O, N/C and COM connectors. I am curious as to what goes where.
 
  #38  
Old 02-26-20, 05:53 PM
S
Member
Join Date: Oct 2013
Location: United States
Posts: 2,859
Received 35 Votes on 33 Posts
K,
I sent you a message.
 
  #39  
Old 02-26-20, 06:26 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
Spott,
I responded to your message via Gmail.
 
  #40  
Old 02-27-20, 01:11 PM
K
Member
Thread Starter
Join Date: Feb 2020
Posts: 40
Received 0 Votes on 0 Posts
On the Taco zone valve control diagrams, the end switch on the control indicates two wires from the end switch go to the 'TT on the Boiler'. Does anyone know exactly where these two wires go on the boiler? Is it the fan switch or does it connect to the wires from the gas valve? What is considered TT or thermostat on the boiler?
 
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: