- Heat pumps
- Pool heat pump
HIGH REFRIG
Pentair HIGH REFRIG on pool heat pump: high refrigerant pressure
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
On the UltraTemp, HIGH REFRIG means the refrigerant high pressure switch is open. Check the water side first: filter pump running, filter and skimmers clean and the external bypass closed.
Safety first
Stop and check this first
- If the alarm returns after fixing the flow, do not keep clearing it: the FIVE ALARMS alarm means 5 faults in one hour and is a sign to call a technician.
- Risk of electric shock: Pentair forbids internal adjustments and asks for any service to be done by an authorized technician with power off.
Safe checks you can perform
- Filter pump running
- Clean filter and skimmers
- External bypass closed and valves open
- Water level and unit left unused
- High pressure switch, TXV and charge
Leave these tasks to a qualified professional
- Do not attempt this professional task: Compressor thermal protector check
- Do not attempt this professional task: High pressure switch test
- Do not attempt this professional task: TXV and charge diagnosis
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Compressor thermal protector check
What they doOn units with LG compressors from 11/1/2020 (except UT70), if nothing above fixes it, the technician checks the thermal protector with the unit powered off.
They must show youthe protector reading with the unit off.
In writingthe result and, if replaced, the reference.
High pressure switch test
What they doThe technician checks the resistance of the high pressure switch and replaces it if it is open once flow has been corrected.
They must show youthe switch reading and the flow check done first.
In writingthe reading, whether the switch was replaced and its reference.
TXV and charge diagnosis
What they doWith gauges, the technician follows Pentair's TXV bulb procedure; if that does not fix it, recovers the charge, checks or replaces the TXV and filter dryer and charges to the data plate.
They must show youthe pressures before and after and the charge on the data plate.
In writingthe pressures measured, the charge recovered and added, the parts replaced and their fluorinated gas certificate.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Filter pump running
- Who:
- you, no tools.
- How:
- check the circulation pump is running while the heat pump calls for heat.
- Result that matters:
- water flowing through the unit.
- If it was off and the alarm does not return once started:
- it was lack of flow.
- If it runs and the alarm returns:
- go to the filter.
- Evidence to keep:
- a photo of the display with the alarm.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
Clean filter and skimmers
- Who:
- you.
- How:
- empty the skimmer baskets and pump strainer basket and backwash or clean the filter following its instructions.
- Result that matters:
- restoring the minimum flow Pentair requires.
- If after cleaning the unit runs without the alarm:
- it was low flow.
- If the alarm returns with everything clean:
- go to the valves.
- Evidence to keep:
- the cleaning date and the filter gauge reading, if it has one.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
External bypass closed and valves open
- Who:
- you, no tools.
- How:
- check the external bypass next to the heat pump is closed and the other valves let water through it.
- Result that matters:
- all the flow going through the unit.
- If the bypass was open and the alarm does not return once closed:
- it was the bypass.
- If the valves were right:
- go to the water level.
- Evidence to keep:
- a photo of the valve positions.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
Water level and unit left unused
- Who:
- you.
- How:
- check the pool level reaches the skimmers; if the heat pump had not run for a long time, Pentair says to cycle it off and on up to 3 times.
- Result that matters:
- the alarm clearing after the cycles.
- If the alarm clears:
- it was the condition after a long idle period.
- If the alarm stays after 3 cycles:
- Pentair says to call for service.
- Evidence to keep:
- a note of how many cycles you did and the result.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
High pressure switch, TXV and charge
- Who:
- an authorized technician certified for fluorinated gases.
- How:
- check the high pressure switch resistance, the pressures and the TXV bulb, and where fitted the compressor thermal protector with the unit powered off.
- Result that matters:
- confirming whether the cause is in the refrigerant circuit.
- If the switch is open with no flow cause:
- it is replaced.
- If pressures return to normal when the TXV bulb is moved:
- Pentair points to debris in the TXV.
- Evidence to keep:
- pressure and resistance readings.
Pressurized refrigerant circuit and mains powered unit next to water. Authorized technician only, certified for fluorinated gases to handle refrigerant.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Heat pumps
- Brand
- Pentair
- Product type
- Pool heat pump
Known code variants
- alarma alta presión bomba de calor Pentair
- HIGH REFRIG
- Pentair heat pump high pressure
- Pentair HP alarm
- Pentair pool heat pump HIGH REFRIG
- Pentair UltraTemp HIGH REFRIG
- Pentair UltraTemp presión alta
- PRESIÓN ALTA
- UltraTemp high refrigerant pressure alarm
What it means
Pentair explains HIGH REFRIG appears when the refrigerant high pressure switch is open. The troubleshooting table starts with water: circulation pump off, insufficient flow (minimum 30 GPM [113.6 LPM]), open external bypass, dirty filters, wrong valve settings or the unit plumbed backwards. Then come internal causes: a bad high pressure switch, a TXV stuck closed, refrigerant overcharge or, on some models, the compressor thermal protector. HIGH REFRIG alone does not point to a failed part: flow is ruled out first.
Warnings and stop conditions
- Mediumeditorial warning
If the alarm returns after fixing the flow, do not keep clearing it: the FIVE ALARMS alarm means 5 faults in one hour and is a sign to call a technician.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
- Highsource verified
Risk of electric shock: Pentair forbids internal adjustments and asks for any service to be done by an authorized technician with power off.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
Symptoms and causes
Probable causes · in order
- Pump off or insufficient flowCommon
The filter pump is off or flow does not reach the 30 GPM [113.6 LPM] minimum because of dirty filters, skimmers or lint traps.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
- External bypass open or wrong valvesCommon
The pump runs, but water goes around the heat pump or a valve is set wrong; fixed by closing the bypass and opening the path.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
- Restriction in the system or unitPossible
Low flow in spa mode, unit plumbed backwards, heat exchanger clogged or internal bypass valve damaged; needs the installer to check.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
- High pressure switch or stuck TXVPossible
With correct flow, the switch is open because it is faulty or the TXV is stuck closed; only technician measurements tell them apart.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
- Overcharge or thermal protectorLess common
Unit overcharged with refrigerant, or on units with LG compressors from 11/1/2020 (except UT70), the thermal protector opened on compressor temperature.
Evidence: ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
Virtual technician
Does HIGH REFRIG still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
ULTRATEMP Heat Pump Installation and User's Guide (P/N 474099 Rev. AA)
Pentair · 2023 · official_doc
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