1 Heating Zone not Working on SR506

jperman47

I fired up the heat in my bedroom this morning for the first time this season and noticed the heat wasn't working and the red light on my SR506 wasn't firing. All my other zones work for both heat and AC, we have 5 zones (1 zone is shared as it was added as part of an addition) that work off a boiler and an indirect hot water heater, I believe it's a hydronic heating system at work here. I have Nest Thermostats in all my zones and have switched them around to see if it was a t-stat issue but still can't get my bedroom zone to fire. Any ideas how to approach this? Thanks!

pedmec

if you know which zone it is in the sr506 just jump it out the t-stat terminals and see if it comes on. This eliminates the thermostat and related wiring. if it comes on you go back to thermostat and check the connections and jump the wires at the thermostat. keep us posted

jperman47

Thanks @pedmec - I'm a bit of a newbie with this stuff. When you say "jump it out at the t-stat terminals" what do I need to do (e.g. disconnect some wires and put them somewhere else?) I think I maybe need to buy some stuff to test as I don't have jumper wire?

Robert_25

You need a short length of wire to “jump” across the R & W terminals of the zone in question.  

jperman47

Ok think I found some spare wire that was marked 24V, so that means keep the R and W of the zone in question in place but add in a small U shaped jumper wire?

jperman47

Ok so I used the jumper and it turned on the red light on the SR506 for the zone in question, assume that means something up stream?

jperman47

This is what the inside of my Nest looks like

jperman47

Paging @pedmec - if the jumper at the Taco unit turned on the zone, any idea what next steps would be in regards to my Nest t-stat?

EdTheHeaterMan

You have eliminated the thermostat and the thermostat wires from the circuit by your first “Jumper” test. Now you want to eliminate the thermostat. You do this by connecting the Red and the White wire at the thermostat. If you connect them together and the circulator works, then the wires are good and the thermostat is bad or programmed incorrectly,


If you connect them and the circulator does not work, then you have found the problem. It is in between the thermostat and the Taco SR relay. Perhaps in the air conditioning unit where both wires are connected together.




Just picking up where @pecmsg left off

jperman47

Ok thanks so much @EdTheHeaterMan

i just connected them and the unit turned on but still no circulator activation / heat so perhaps next stop is going to check the unit in the attic. Will report back 

jperman47

Checked the handler in the attic but not sure what I am looking for, attached some pics. I am wondering if during the renovation of my addition they accidentally cut a wire that ran off of the unit and alongside the wall where we put an addition in...grasping at straws at the moment





If I put the jumper in place on the Taco SR506 will that allow me to use the heat with the Nest controlling temps (e.g. turn on / off when it reaches set temps) or will it just run continuously until the jumper is removed?

Jamie Hall

It would just run until you took the jumper off. But did you say that when you connected red and white at the thermostat that the unit turned on but the circulator didn't? But when you jumpered at the Taco the circulator did start? What, exactly, do you mean by "unit"?

EdTheHeaterMan

I can see that you have a Hydro-Aire type system. your thermostat connects to the First Co. air handler. when there is a call for heat the fan will blow air thru the hot water coil.

The thermsota tis operating properly to turn on the heat. there is a part called a relay inside the air handler that is not connecting the call for heat to the circulator control.

Your problem is inside the First Co. air handler. Are you up for looking at wiring diagrams?

jperman47

Jamie Hall said:

It would just run until you took the jumper off. But did you say that when you connected red and white at the thermostat that the unit turned on but the circulator didn't? But when you jumpered at the Taco the circulator did start? What, exactly, do you mean by "unit"?

When I connected the red and white a the thermostat, the air handler turned on and cold air started blowing but the circulator and red light on the Taco did not turn on. When I jumpered the R & W on the Taco unit for the zone in question, the circulator turned on and the light turned red.

EdTheHeaterMan

By the process of elimination you have ruled out the thermostat connection to the First Company Air Handler. and you have eliminated the Taco SR zone control and boiler. the section in red is the problem area.

Will be watching the Eagles Game for the next few hours. I' check in later this evening

jperman47

EdTheHeaterMan said:

By the process of elimination you have ruled out the thermostat connection to the First Company Air Handler. and you have eliminated the Taco SR zone control and boiler. the section in red is the problem area.

Will be watching the Eagles Game for the next few hours. I' check in later this evening

Thanks Ed, at least I've now whittled it down based on your help. I think something was cut when they did the addition work (which was over the summer so we never tested the heat). I will reach out to my contractor tomorrow and see if he can have someone take a look.....I surmise the only cause here is something wrong with the wires running from the Air handler to the Taco controller

neilc

at the Nest ,
don't we need a jumper between RC and RH ?
or does Nest do that internally in the setup ?

Did this work before the Nest ?

109A_5

Hello @neilc,



https://support.google.com/googlenest/answer/9250973?hl=en

neilc

always learning ,

last question still stands,

neilc said:

Did this work before the Nest ?

pedmec

sorry, was watching my patriots try and play a football game. ed has you going in the right direction. id the hydroair being used as one zone or is it being zoned too?

jperman47

neilc said:

always learning ,

last question still stands,

neilc said:

Did this work before the Nest ?

Yes has worked for 5+ years

jperman47

pedmec said:

sorry, was watching my patriots try and play a football game. ed has you going in the right direction. id the hydroair being used as one zone or is it being zoned too?

This one in question is just 1 zone (bedroom only)

pedmec

so your hydroair only feeds one bedroom?

pedmec

From your pics it looks like there are 4 takeoffs off of your hydroair unit so there must be 3 other locations not getting heat too.

jperman47

pedmec said:

From your pics it looks like there are 4 takeoffs off of your hydroair unit so there must be 3 other locations not getting heat too.

Yes, those are all just going into differing vents in my bedroom + maybe some in my closet and master bathroom - all not getting heat. I think perhaps there is something wrong with the specific wire that serves to communicate between the hydroair in my bedroom / bathroom / closet and the Taco controller downstairs?

pedmec

must be a big bedroom for one system. if that's the case then, yes, looks like your 2 conductor from the air handler to the zone panel has been severed.

EdTheHeaterMan

To get some heat in the bedroom, You could jumper the TACO SR zone and use the thermostat to turn the fan on and off. You will be wasting some fuel but you will get heat thru the night until the repairs can be made.

You asked that before but without more info I could not say YES to that.

But now I can. YES

jperman47

EdTheHeaterMan said:

To get some heat in the bedroom, You could jumper the TACO SR zone and use the thermostat to turn the fan on and off. You will be wasting some fuel but you will get heat thru the night until the repairs can be made. You asked that before but without more info I could not say YES to that. But now I can. YES

Awesome! Thankfully not that cold in the northeast and I will be able to get this all fixed ahead of the real winter. My contractor will handle since he / his subs did this during renovation when they were probably cleaning out old wires. I take it the solution is for the HVAC wire to just get re-run between my handler and my Taco?

pecmsg

EdTheHeaterMan said:

You have eliminated the thermostat and the thermostat wires from the circuit by your first “Jumper” test. Now you want to eliminate the thermostat. You do this by connecting the Red and the White wire at the thermostat. If you connect them together and the circulator works, then the wires are good and the thermostat is bad or programmed incorrectly,


If you connect them and the circulator does not work, then you have found the problem. It is in between the thermostat and the Taco SR relay. Perhaps in the air conditioning unit where both wires are connected together.




Just picking up where @pecmsg left off

I believe you mean @pedmec

EdTheHeaterMan

@pecmsg OOPS, honest mistake, knowing your passion for NEST products.

jperman47

HVAC guy came and confirmed that I do indeed have a cut wire between the air handler and the relay switch. Thank you to all for leading me in the right direction. Next up: electrician to run a new wire