New Raypak 5450 heat pump...worked for a day, now high pressure trip/lockout

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GettingThere

New member
Mar 17, 2020
3
Sebastian, FL
Hello,

A few days ago, I installed a new Raypak 5450ti heat pump (103k BTU). I plumbed it with 2" pipe from the filter housing to the heat pump inlet, as well as from the heat pump outlet to the salt water chlorine generator cell. I have 2" ball valves going to/from the heat pump, with a 2" bypass, also with a ball valve so I can bypass the heater when not required and drain it as needed.

The day I installed it, the pool temp was about 72F, ambient was in the low 80s. The unit ran like a champ and warmed the pool to the set 84F level with no problem, with the pump (pentair SuperFlo VS) running at 2600RPM and heat pump running continuously. The next day, kids jumped in and noted that the pool was cooler and jets were not pumping out warm water, so I investigated. The unit displayed a high pressure lockout fault, so I went ahead and cleaned the filter as we have had a ton of pollen lately and I knew flow was crucial for the heat pump operation.

Long story short, it has changed nothing. Compressor kicks on and runs for 3-4 minutes and the high pressure trips. while the compressor is running, the discharge air from the unit is quite cold and jets are flowing noticeably warmer water, so some heat transfer is taking place. I have tried max pump RPM, running with no filter, low (2000) RPM, cracking the bypass valve in various positions, etc. The heat pump is just outside the pump shed. I used about 30 feet of 2" pipe to run both inlet and outlet runs from filter housing all the way back to the salt cell. All-in, there are (Qty 9) 90-degree bends and the 3 ball valves, and the heat pump is on the same elevation as the pool pump/filter. I tried to simplify the plumbing runs as much as possible.

I have called Raypak and they are sending out a tech Friday to inspect the unit itself, but I'd like to make sure I have tried all that I can from a DIY perspective...I only have automotive A/C gauges, so no chance for me to check pressures on this thing. I have found no measurements in the installer menu on the unit that amount to much insight. Also, no one locally sells flow meters that I can plumb in in the meantime.

Any thoughts on what to look for / try next?

Thanks in advance for any advice!
 
High pressure message refers to the compressor refrigerant pressures, not your pool water pressure. Probably low refrigerant or a compressor problem. It’s under warranty so let them figure it out.

Pressures are usually on a label on the HP. Anyone who works on AC systems can check it.
 
High Pressure Switch Lockout.

If the high pressure switch opens, the control de-energizes the compressor output and the fan continues to run for 15 minutes after the HPS opened and the display will show “Hi Press Trip”.

If the high pressure switch trips 7 times in a single cycle, the display will show “Hi Press Lockout” and the unit will be locked out of operation for 4 hours.

The unit will automatically reset after 4 hours or the lockout can be manually reset by pressing the MENU button or cycling the power.

The high pressure switch must close for 3 seconds for the control to recognize it as closed.
Click to expand...

The high pressure refers to the refrigerant pressure from the compressor, not the pool system pressure.

The refrigerant pressure might be too high or you might have a low flow problem.

Do you have a picture of the installation?

What flow rate do you have going to the heat pump?
 
Thanks for the replies. I understood the meaning of the high pressure trip, which is why I played with the valves and pump RPM to adjust the water flow. Currently, I only have an estimate of flow based on the Pentair flow chart...it should be well above 50GPM at 2800RPM. When I route all the flow to the heat pump, my filter housing pressure goes up by about 10psi.

I'll see what the tech says Friday with some investigation of the heat pump itself, and I'll report back here for reference.

Thanks!
 
Are you sure that you're using the valves correctly?

The bypass should be closed and the two valves going to the heat pump should be open.

Maybe the internal bypass is defective?

Open the unions and make sure that there's nothing blocking the inlet or outlet.
 
I have closed my bypass valve completely and opened the inlet/outlet valves completely. Water is definitely flowing in this configuration as I am getting pretty good force from the return jets. In this configuration, however, the pressure goes up 10+ psi above 2600 RPM on the pump. I'm not sure if this is expected for the 5450ti internal plumbing setup. I didn't think about the internal bypass on this unit. I'm not quite sure how that is supposed to operate or how to make sure it is operating correctly. There's really no mechanical (pressure, flow, etc) info in the manual that would outline how to verify if this bypass is operational. Hopefully, the tech can verify everything when he/she comes...either a defective component or defective DIY install
 
Here is the expected pressure increase based on water flow rates through the heat pump.

Gpm........Psi
30..............4
40..............7
50............10
60............11
70............12
80............13

Based on a 10 psi pressure increase, that implies a 50 gpm flow rate.

What is the filter pressure?

Check the flow rate based on the pump head curve at 2,600 rpm at the filter pressure to see if it's 50 gpm.
 
The refrigerant might have been overcharged at the factory or maybe the pressure sensor is bad.

There might be too much water going through the internal bypass due to a bad bypass or maybe something clogging the heat pump inlet.
 
Was there any resolution to this?

I have a brand-new (literally manufactured last month and installed a few days ago) Raypak R6450ti-E that is giving me this exact same error message. Looks like we'll be calling Raypak in the morning.

Hopefully they can get us up and running quickly. We bought it because Raypak is supposed to be pretty good quality stuff, so having it not work straight out of the box is...concerning.
 
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+1, new R8450ti-E doing the same once in awhile. I called Raypak but they can't send anyone out currently. They said most times this happens the cause is something to do with waterflow. It happens to me both when the pump is on any speed. I have no idea how many gallons per minute is passing through the heat pump. Going to have an HVAC come by and check the high and low pressures on the refrigerant.
 
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monkeysocks said:
+1, new R8450ti-E doing the same once in awhile. I called Raypak but they can't send anyone out currently. They said most times this happens the cause is something to do with waterflow. It happens to me both when the pump is on any speed. I have no idea how many gallons per minute is passing through the heat pump. Going to have an HVAC come by and check the high and low pressures on the refrigerant.
Click to expand...


Start your own thread and post pics of your equipment pad and heater plumbing. We have spotted a few installation errors.
 
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I'm not OP, but Raypak said they'll have someone at our house today. Guess we'll see what's going on.

Didn't see any issues with the installation of the heater, aside from the lack of a bypass installed with the plumbing (it isn't necessary for our pump size and heater size, according to Raypak's literature), but I can do that myself later this summer just so I can bypass the heater for SLAMs.

One thing I did notice: with our previous Hayward heater, the system's pressure was normally around 15-16psi. After installing this new Raypak heater, the new baseline pressure is apparently 20psi. Maybe it is more restrictive than the old heater?
 
Last edited:
sccm_sysadmin said:
One thing I did notice: with our previous Hayward heater, the system's pressure was normally around 15-16psi. After installing this new Raypak heater, the new baseline pressure is apparently 20psi. Maybe it is more restrictive than the old heater?
Click to expand...

Was your old Hayward heater gas and your new Raypak a HP? If so, HPs are by design more restrictive then gas heaters.
 
sccm_sysadmin said:
Only difference was size: the Hayward was something like 105k BTUs, the Raypak is 119k BTUs.
Click to expand...

The Raypak has a spiral titanium tube heat exchanger that may have more restriction. Different design with different performance.
 
Heat pumps have horrible hydraulic design. The tubing is way too small and presents way too much restriction. The small opening is easy to clog if anything gets in the line. In my opinion, the tubing diameter needs to be twice as big. Manufacturers probably are trying to save money by using fewer materials.
 
Makes sense to me, on both counts.

A natural gas heater would have been great. We have natural gas service to the house but the original homeowners didn't have a line trenched out to the pool (75-ft through a wooded area, and we don't know the exact locations of the electric and plumbing lines for the pool). Combine the need to trench a line with the low cost of electricity in my area (8.7cents/kWh) compared to natural gas pricing, and the heat pump was the way to go.
 
New Here and appreciate this thread!

So I have a R6450TI-E and was having the same issue until someone posted the flow guidance above. I found that when my variable speed pump (VSP) is on its highest setting the high pressure trip would kick on when the compressor would engage. However, when at a lower speed all is fine.

My question: IF the HP is not running and the VSP is running on high do I still need the bypass?

My thought was that I would program the automation that when the HP needs to turn on it would set the VSP to the proper speed.

Thanks for any guidance.

JAX
 
jaxsully said:
My question: IF the HP is not running and the VSP is running on high do I still need the bypass?
Click to expand...

Yes, high flow rates can erode the heat exchanger. That is what created the Grand Canyon.
 

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