Combi boiler can I keep it simple?

Users who are viewing this thread

Jacob Hellenberg

New Member
Messages
4
Reaction score
0
Points
1
Location
Michigan
Hi everyone,

My tankless hotwater tank broke and the 35 dollar part is not available anymore. So I bought a new Rheem combi boiler because the Mini Thurm boiler is 35 years old. Just had our first baby 3 months ago and and we have no hot water.

I thought the install shouldn't be too bad but right off the get im confused because this has the TT terminals to trigger the heat. I'm used to the standard 24v thermostats. Long story short. Does jumping the TT Terminals together Trigger the demand for heat? If so can I wire the three end switches together and tie to the TT terminals to trigger on the boiler? (I have 3 pop top Erie zone valves) My old system did not have a zone controllers just 3 thermostats that drove the zone valves open and than the end switches activated the demand for the boiler. Can I keep it this simple and use 24v thermostats isolated to only run the zone valave motors and end switches only to trigger TT?

Any insight on this would be more than appreciated!
 

Jacob Hellenberg

New Member
Messages
4
Reaction score
0
Points
1
Location
Michigan

Attachments

  • 20200820_201016.jpg
    20200820_201016.jpg
    54.7 KB · Views: 130
  • 20200820_201038.jpg
    20200820_201038.jpg
    62.2 KB · Views: 114
  • 20200820_201041.jpg
    20200820_201041.jpg
    80.1 KB · Views: 128
  • 20200820_201042.jpg
    20200820_201042.jpg
    79.5 KB · Views: 119
  • 20200820_201104.jpg
    20200820_201104.jpg
    135 KB · Views: 141
  • 20200820_201159.jpg
    20200820_201159.jpg
    88.7 KB · Views: 129
  • 20200820_201229.jpg
    20200820_201229.jpg
    70 KB · Views: 132

Jacob Hellenberg

New Member
Messages
4
Reaction score
0
Points
1
Location
Michigan

So I bought a taco Taco zcv405 zone controler. I thought it would have the 10vdac out on it but does not. It only has a isolated end switch and says to TT.

Where do I get the 10vdac from so that I can wire it to the end switch to trigger on. It does have the outdoor thermometer but says it is not needed. What do you recommend? I noticed when running a jumper wire from the circuit board (which was showing 4.5vdc) to the TT in the picture above it would turn on, but would only run on low demand up too 110 degrees output. I'm guessing if it had the full 10vdac going to it ,it would be the full 180 degrees? Is there a transformer I need to buy outside of the zone controller and combi boiler? Any help at all to generically explain how these systems work would be greatly appreciated!
 

amodedude1

New Member
Messages
3
Reaction score
0
Points
1
Location
Philadelphia
Is this a Rheem Prestige Series? Can you provide the actual specific model number? The photo you took is of the heat exchanger and it is not the manufacture of the boiler. "Kiturami Co." is just a manufacture of heat exchangers, this same heat exchanger is used on Noritz CB-199/180 models, Rheem, HTP, Westinghouse, Larrs, and more manufacturers as well so that photo does not really help much. Take a picture of the giant sticker on the side (probably the right hand side). What is the 35$ part that broke on your old one?

Anyway, you don't use the 10VDC. You were correct about TT:

Does jumping the TT Terminals together Trigger the demand for heat?

Yes, you got it! Take a jumper and jump TT. It's exactly the one you have your finger pointed to in the image "20200820_201041.jpg". The one that says "Heat Demand Input 10VDC" is for something different, do not hook up a 24VDC thermostat or source to this. It's for 10VDC building control systems which you probably don't have.

The photo "20200820_201038.jpg" shows your finger pointed to the two terminals where you hook up your outdoor temperature sensor. This is the right spot for that (the right hand side two terminals your finger is pointed to). The main end switch goes to TT on the boiler. See the manual here: https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Taco-ZVC406-EXP-4-Install.pdf Yours is probably similar to that. "TO: "TT" ON BOILER" is what goes to your boiler. Hope that helps!
 
Last edited:

Fitter30

Well-Known Member
Messages
2,638
Reaction score
413
Points
83
Location
Peace valley missouri
T to T is looking for a dry set of contacts like a end switch from a zone valve. Whats turning the pumps on?
 
Last edited:
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks