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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 for 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.
Or if you need a new Raypak heater, check these new models:
- Part Number: 014786
- Model Number: P-R156A-EP-C
- Built to withstand various weather conditions, perfect solution for environments requiring efficiency, convenience and versatility.
- Intermittent spark ignition pilot safety controls. Pilot only comes on when there is a call for heat.
- Designed for easy installation on above ground pools, smaller in-ground pools, and spas
- Standard 120v 3-prong power cord or can be easily converted to 220v
Chart for SW Open Error Causes and Fixes
| Sw OPEN ERROR CAUSES | Sw OPEN MAIN FIXES |
| CLOSED SHUT-OFF VALVES | OPEN THE INLET/ SHUT OFF VALVES WHERE NECESSARY |
| CLOGGED FILTERS | CLEAN THE FILTERS |
| DIRTY OR BLOCKED BASKET AND SKIMMER | CLEAN THE BASKET AND THE SKIMMER |
| LOOSE WIRES OR FAULTY WIRING ON THE PRESSURE SWITCH | CHECK FOR LOOSE WIRES OR FAULTY CONNECTION |
| PRESSURE SWITCH NOT CORRECTLY SET | ADJUST THE PRESSURE SWITCH |
| DEFECTIVE/FAILED RECIRCULATION PUMP | REPLACEMENT OF RECIRCULATION PUMP |
| DEFECTIVE PRESSURE SWITCH | REPLACE THE PRESSURE SWITCH |
Steps to diagnose the Sw open message
· Ensure there are no closed water inlet valves.
· Check if any bypass valves 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 for any closed valves. Ensure that the water valves are open and in the correct positions to allow the normal water flow to the pool.
2. Are the Inlet/outlet bypass valves on? If any bypass valves are open, close them to allow for the full flow of water to the heater. An activated bypass valve will restrict the water flow to the heater, which 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.
- Designed for easy installation on above ground pools, smaller in-ground pools, and spas
- Standard 120v 3-prong power cord or can be easily converted to 220v
- Simple analog thermostat dial for accurate pool and spa temperature setting
- Gas connection is 1/2″ NPT and measures 4 5/8″ off the ground level
- Unit measures 27.5″ H x 12″ wide X 24″ Deep
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 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
- To gain access to the pressure switch, you’ll need to remove the return access cover. This is located opposite the water connection side.
- Start the system water pump and ensure water is flowing normally to the pool.
- Turn on the power for the pool heater.
- If the heater lights, that means the water pressure is within the normal range and you may not need to adjust the pressure switch
- Now, adjust the set point temperature to 40 degrees.
- 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 regularly (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.
HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.