Raypak Pool Heater Sw OPEN Code: (Causes & Fixes)

If you are dealing with an Sw Open message on your Raypak heater, I have a solution for you! A Raypak heater is typically equipped with a pressure switch that only allows the heater to fire up when there is sufficient water flow.

The Raypak Pool Heater RollOut Sw OPEN error is related to the water flow to your pool heater. That means that this message is an indication that there is a restriction of water flow into the heater.

It must be noted however that the pressure switch is only suitable as a means of determining water pressure in a heater installation where the inlet/outlet water piping is 150 mm below or above the pool level. Otherwise, it doesn’t work and could be the reason for the SW open error.

Chart for SW Open Error Causes and Fixes

Sw OPEN ERROR CAUSESSw OPEN MAIN FIXES
CLOSED SHUT-OFF VALVESOPEN THE INLET/ SHUT OFF VALVES WHERE NECESSARY
CLOGGED FILTERSCLEAN THE FILTERS
DIRTY OR BLOCKED BASKET AND SKIMMERCLEAN THE BASKET AND THE SKIMMER
LOOSE WIRES OR FAULTY WIRING ON THE PRESSURE SWITCHCHECK FOR LOOSE WIRES OR FAULTY CONNECTION
PRESSURE SWITCH NOT CORRECTLY SETADJUST THE PRESSURE SWITCH
DEFECTIVE/FAILED RECIRCULATION PUMPREPLACEMENT OF RECIRCULATION PUMP
DEFECTIVE PRESSURE SWITCHREPLACE THE PRESSURE SWITCH

Steps to diagnose the Sw open message

·         Ensure there are no closed water inlet valves.

·         Check if there are any bypass valves that are open.

·         Check if the filter is dirty

·         Inspect the pump basket and skimmer basket to rule out any obstructions/blockages

·         Look out for loose wires on the pressure switch

·         Is the pressure switch correctly set?

·         Check if the recirculation pump is working

·         Test for voltage across the ends of the pressure switch

How do you fix the RollOut Sw pool heater open error?

1.       Check for any shut-off valves. Ensure that you inspect the plumbing and check if there are any closed valves.  Ensure that the water valves are open and in the correct positions to allow the normal flow of water to the pool.

2.       Are the Inlet/outlet bypass valves on. If there are any bypass valves that are open, close to allow for the full flow of water to the heater.  An activated bypass valve will restrict the water flow to the heater and this could result in the SW open Code.

3.       Find what’s obstructing the intake and the heater should work

4.       Clean the water filter. Make sure the pump basket and the skimmer basket are clean and free of debris or leaves. Generally, clogged filters are a common cause of the restricted water flow to the heater. Try passing the filter and see that that fixes the problem. If it does, your filters might be clogged and just need some cleaning. Depending on your model, try cleaning the cartridges or backwash/backflush your filter and see how it works.

5.       Test the ends of the pressure switch for continuity using the multimer. Check for loose wires on the pressure switch. If there is no voltage, the pressure switch is probably defective. In that case, a replacement should solve the problem.

6.       When the pressure switch is not correctly set, it can trigger the SW error. If necessary, you’ll have to adjust the pressure switch (see the next section of this guide on how to adjust your pressure switch.)

7.       Check for loose wires on the pressure switch and securely attach those that are loose.

8.       Ensure the recirculation pump Is working and that is not set to low

One important thing to note is that even if the water intake in the pool seems to be normal, there still could be a restriction of water flow enough to prevent the pressure switch from closing, causing the heater to shut down.

How to adjust the water pressure switch

  1. To gain access to the pressure switch, you’ll need to remove the return access cover.  This is located opposite the water connection side.
  2. Start the system water pump and ensure water is flowing normally to the pool.
  3. Turn on the power for the pool heater.
  4. If the heater lights, that means the water pressure is within the normal range and you may not need to adjust the pressure switch
  5. Now, adjust the set point temperature to 40 degrees.
  6. If the heater doesn’t light in step 5 then you’ll need to make adjustments to the pressure switch.
  • Turn the pressure switch knurled adjustment wheel in a clockwise direction
  • Continue turning it until the heater ignites
  • At the point where the heater ignites continue further turning for another 1/4 turn

7.       The pump should be cycled on and off a few more times to ensure that the adjustments made are correct.

Final Thought

We have seen that the SW open message on your Raypak heater is commonly triggered by issues relating to the pressure switch. That is a problematic pressure switch or an insufficient flow of water into the heater.

That said, there are a few things you can do to keep your pool heater running in great condition. These include

1.       Monitoring chlorine and PH levels of your pool water on a regular basis (depending on what is recommended in the user manual.)

2.       Do not run your heater if the water balance is out of the parameters specified by your manufacturer.

Thank you for reading.