Odd Raypak 406A heater controller issues

KBB_TX

New member
Dec 7, 2021
1
Galveston County, TX
Pool Size
12
Surface
Plaster
I have a Raypak P-R 406A-EP-C pool/spa heater running propane; it's about 15 years old. It has a 013464F controller board that replaced the original when the latter failed in 2015.

That controller board now behaving very oddly. In SPA (local) mode, it seems to run fine. In REMOTE mode it only heats until it reaches the SPA temperature setting, disregarding what the remote says to do. The SPA max temp is set to 104F, the default. By default the SPA mode set temp. is 65F and despite the signals from the remote computer it won't try to heat; if set to 80F for SPA mode it does heat in REMOTE mode, but only to 80F, ignoring the remote call for heat.

I have reset the board to Factory Settings several times and reseated the connections. The power supply is at 26.9VDC and the flame strength is 8 Good. Has anyone else seen this failure and found a fix other than replacing the board again?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
33,629
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Welcome to TFP.

Let's get clear on some terminology so we are speaking the same language.

What remote automation is your heater connected to?

In REMOTE mode it only heats until it reaches the SPA temperature setting, disregarding what the remote says to do.

You have two independent thermostats. One on the heater and one on the automation. If by "SPA temperature setting" you mean the setting on the heater then that is correct. Even if the REMOTE is a higher temperature setting it will only heat up to what the heater is set to.

The SPA max temp is set to 104F, the default.

That is what the heater temperature setting should be set to. Then the REMOTE will control the temperature.

By default the SPA mode set temp. is 65F and despite the signals from the remote computer it won't try to heat; if set to 80F for SPA mode it does heat in REMOTE mode, but only to 80F, ignoring the remote call for heat.

You just said " The SPA max temp is set to 104F, the default." Now you say it is set to 65F. Why?

Set the heater temperature control to 104 and use your REMOTE to set the desired water temperature.
 

KBB_TX2

New member
Dec 9, 2021
3
TX
Thanks for replying.

Just to be clear, this Raypak board has separate settings for SPA Set Temperature, SPA Max Temperature, POOL Set Temperature & POOL Max temperature. The SPA & POOL Max Temperature are safety limits and have never been changed from their default 104F value. The SPA & POOL Set Temperature should only be used in local SPA or POOL mode and for a decade have been left at their default of 65F.

The remote system is a Jandy, but that can't be the problem. The Jandy system sends only 2 signals to the Raypack board; SPA or POOL Demand Heat and no signals run from the Raypak back to the Jandy.

When the Raypack board is set to local control SPA, a mode we've never used apart from testing, it behaves exactly as it should and heats to the SPA Set Temperature and maintains it properly. We have always (for 10 years) left SPA & POOL Set Temperature at their default of 65F. We have always used Remote Mode and the signal from the Jandy controlled the temperature by turning Demand Heat on & off.

When in Remote Mode, it used to only heat when it got a Demand Heat from the Jandy and just ignored the SPA Set Temperature, but always displayed the Set Temperature as 65F. That is exactly as shown in the Raypak manual P/N 241530 under REMOTE CONTROL AND INSTALLATION.

Now, suddenly, when in Remote Mode it will only heat when BOTH that it gets Demand Heat from the Jandy AND when the Raypack temperature sensed from its own dual thermistors and shown on its display are below the SPA Set temperature.

As a temporary workaround, I set the SPA Set Temperature to 102F; since now in Remote Mode BOTH the Raypack reported temperature must be below the SPA Set Temperature AND the Remote Mode Demand Heat must be present to start heating. I have it working again with only the Jandy side regulating the target temperature by setting the Raypack SPA Set Temperature far higher than the Jandy temperature setting.

However, this mode of operation doesn't leave me sanguine, as clearly something has suddenly changed within the Raypack controller. I'm concerned it could presage a greater failure and I'm rather curious whether other Raypak users have seen this problem and have possibly fixed it.

Following the factory manual instructions, I've tried a reset (Set Factory Defaults) of the board several times using Program Button SW1 on the back of the board. I've gone through all the menus and all the messages from the board appear normal.

While the Raypak board has diagnostic messages about various sensors, it doesn't lend itself to any detailed troubleshooting of the board itself. I have been unable to locate any schematics of the board, just those showing how to connect it to external devices. Right now it appears that the board will still fail safely.
If you could point me to detailed schematics of this board, I'd appreciate it. Thanks again.
 

1poolman1

In The Industry
Jul 14, 2014
967
Sacramento
The Jandy only controls temperature by completing the control circuit in the heater itself based on the temperature it reads independently of the heater. I routinely get service calls on heaters that "only heat to ---degrees but my Jandy (Pentair, Hayward, etc.) is set to a higher temperature."
I usually find that the heater has been set to a lower temperature, though the customer will never admit to it (must have been one of my kids, etc).
The heater itself will still determine the water temperature if it is set below the controller's setpoint. The automation does not override or suspend heater controls in newer heaters.
 

ajw22

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TFP Guide
Jul 21, 2013
33,629
Northern NJ
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The way your heater behaves now is the way Jandy, Hayward, and Pentair heaters act when controlled by the "Firemans Switch". I don't know if the board was a bit different 15 years ago but there is nothing to fix with the new board you installed,
 

KBB_TX2

New member
Dec 9, 2021
3
TX
Thanks again for your advice. There never has been a Fireman Switch installed, but it's a very good idea to check that the nothing has broken @ the P2 connector - thanks.

The original board from 2006 failed in 2015 such that it always reported Demand Heat even with P8 to the Jandy system unplugged; the SW1 reset didn't change that. When I put in a new replacement board using the defaults. I did get a "Flame w/o CFH" message when I tested the board before I'd even turned the propane back on. Having seen flame rectification errors before in other (Honeywell) ignition systems due to organic films, I used WD40 to clean the blue high voltage lead from the board to the ignitor and the problem went away and has not reoccurred. Afterward, I did ask Raypak support about the messsage, but the fellow there was quite hostile. While Raypak makes good products, I have never encountered a nastier tech support.

it ran fine until 2019, when mice built a nest near the ignition - when it did finally ignite the explosion made a 4' fireball and blew the front off the R406A. After cleaning out the debris it worked fine again, except that the display board lost over half of its display. When this new issue appeared in 2 months ago I put in a new display board to read any messages . The new display reported no problems. We have no kids, have had no visitors since COVID, and only I have touched the controls in any way and hadn't touched them since I'd put in the replacement board in 2015.

It seems to be working OK as is; perhaps it was wrong before and is right now (P/N 241236 p37 suggests that might be the case). That leaves 3 possibilities:
  1. both boards ignored SPA Set Temperature when in Remote Mode, but suddenly the new board started using it
  2. the SPA Set Temperature has always been set to 65F, but both thermistors reported a temperature very, very low so the Raypak reported temperature was always below 65F and I never noticed it.
  3. for 10 years I have done ever SW1 reset incorrectly and the new board came with the SPA Set Temperature >=102F
All seem improbable, but perhaps the 2nd is most likely. Both thermistors agree, but the board is reporting a temperature about 8F higher than the actual water temperature. The thermistors share a common return and a spurious high resistance in that leg could cause both to report a low temperature. I measured the resistance of the thermistors at P1 on the Raypak board and they both were at spec (P/N 241236 p 46), but perhaps weren't earlier.

I will order a new dual thermistor assembly 009577F and put it on the shelf for now.

Thanks again for all your help; I feel confident this isn't too big a safety issue.
 

ajw22

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KBB_TX2

New member
Dec 9, 2021
3
TX
According to the Raypak instructions, the Fireman Switch is an optional switch installed across pins 13 & 14 on board connector P2 required in certain jurisdictions and is not the same as the 2 remote Demand Heat inputs on connector P1. Perhaps other vendors use different terminology; this is the only in-ground pool experience I've ever had, but I have read all the documentation very carefully.

While reading reviews while shopping for a replacement dual thermistor today, I saw that numerous people reported that many of the replacement dual thermistors read low by 30F. If that was the case here, then the board believed the temp was 65F, not the actual 95F, and hence the board was doing the right thing (possibility #2) until the thermistors suddenly jumped from reading 30F low to reading 8F high. It is possible that the dual thermistor had been replaced before I bought this place, but I have no evidence of that. Both thermistors would have had to change by a very similar amount or there would have been an error message and the board would have shut down all heating.

In my experience, usually one must individually calibrate thermistors as they vary quite a bit, even the expensive ones we use aboard the ISS in radiation detectors. In this setup, the two thermistors must agree as a safety precaution (the tolerance is not specified), however, Raypak probably should have used 4 wires rather than 3 and having the two thermistors share a common. Any increase in resistance on that common line would shift both temperature readings down by the same amount.

Again, thanks for your help. I'll let the system run as it is and keep a replacement thermistor on the shelf just in case.
 
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