Indirect Water heater Calling for heat but Boiler won't turn on

Badger99

Hello:

I am having a problem with my boiler not heating my domestic hot water when calling for heat. I have a 2 zone Erie SR201control with priority. Priority is on hot water and 2nd zone is on infloor heating. The infloor heating thermostat turns on the boiler when calling for heat; however, the boiler will not turn on when indirect water heater calls for heat. If I completely kill the power to the SR201 and turn it back on, the priority zone light turns on immediately and the boiler turns on and heats the water heater. It may work then for several hours, 1-2 days, or maybe more, but eventually it will not heat the water heater until the power is shut off and on….. just turning the boiler off and on does nothing. The power to the Erie SR201 has to be shut off. Thanks for any advice

SR201.jpg

GGross

It's hard to make out your wiring, but is the priority function setup correctly? There are 2 options, priority or priority plus. the plus mode has a timer that will cut out the priority zone after a certain runtime and not allow another call for a set amount of time. turning the control off and back on would likely reset that timer allowing for a priority call, but then we would want to know why the prio zone is calling for more than an hour straight.

HomerJSmith

I would say it is probably a wiring intermittent connection. Check the bypass jumper, switch the relays (you can lightly tap on the relay cube when the DHW is inoperative). Check all wiring connections.

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/SR201%20-%20Product%20Overview.pdf

Badger99

I think it is wired correctly as it worked at one time, but I will double check. According to the manual the "Priority" setting locks out non-priority heating zones indefinitely, but "Priority Plus" allows non-priority heating zones to be locked out for up to one hour. Could one of the Omron general purpose power 24 VAC relay

SR201.jpg

on the zone control be bad?? See updated picture with circles.

HomerJSmith

Those are relay cubes. You can switch them and see what happens. Also, I would check as a last resort the solder foil backing of the Erie SR201 board for broken solder joints, especially at the relays.

EdTheHeaterMan

This is the Diagram for your system

the blue area is the Ice-cube relays (as we like to call them) that you may switch to see if that solves your problem. Your problem sounds like the 1K normal Open contacts are not always making complete contact. By cycling the power to the SR201 off then on you create a second chance for thow 1K contacts to make.

If you swap the relays, and the CH heat circulator fails of activate, then you know that you have a bad relay, and you can replace it.

Badger99

Thanks for the help.

So I swapped out the relay cubes and it worked fine for a little under a week and then reverted back to needing to be powered on and off. The relay cubes were inexpensive so I bought 2 new ones. That also worked for a bit but not working again this morning. I removed the cubes and sprayed the board with contact cleaner and re-inserted the cubes. I don't see any issue with solder joints but something must not making a good connection or something. The system is heating the DHW again - but we will see for how long.

Jamie Hall

I keep saying this… check all your connectors — plugs and sockets. Pins tight? Fit well? Connections good? Then check all the wires? No chewed insulation? No broken wires (pull on them if necessary — intact wires won't stretch…). Check ground connections.

HVACNUT

Do the thermostat wires for the indirect go from the Erie panel to the black relay on top, or does it go right to the indirect thermostat/aquastat. Actually, what IS controlling the indirect? Does it have lights?

Badger99

The aquastat wires go directly from the indirect water tank to the Erie panel.