I have Fault code F31 / Flow / !flow fault on my heat pump (WPM or Touch screen based). What does this mean?

Fault code F31 / Flow fault means that the heat pump controller is detecting that there is insufficient flow of water between the heat pump and the property.

This will require your installer to attend and check the following-

• Check the flow rate of water from the heating circuit to the heat pump is high enough compared to the published nominal flow rate required for that model of heat pump. Check any inline strainer or mag cleaner for debris which could be restricting flow.

• Check the heating circuit water pressure is sufficient (typically between 1.0-1.5 bar) and that there is no air in the heating circuit that could impede water flow. 

• Check that no isolation valves have been closed by accident

• Check what the flow & return temperatures are reading when the system is also performing Hot Water or Swimming pool functions if set up for that.

• If the auxillary M16 pump has been fitted, is it configured to come on when it is required for heating and/or hot water production? Check in Installer menu (Hold Menu + Enter) - Settings - pump control - M16 function as M13 or M16 function as M18 (hot water) and tick as needed.

• If multiple heat pumps are connected to the same hydraulic circuits, does the flow fault only happen when multiple heat pumps are running? If so, have check valves been installed were required and is the pipe sizing between the heat pumps and the building load been appropriately sized for the flow rate required for multiple heat pumps to run together?

• There is a rare possibility of a faulty flow switch or flow sensor (if fitted). This will need to be investigated by a service agent. To raise an in guarantee request submit a ticket below.

Note: If our service engineers attend to a flow fault which is due to the flow rate not meeting nominal specification and not the fault of a flow switch / flow sensor, then the visit will be chargeable.

Require additional help? Please follow link below

https://glendimplexservice.freshdesk.com/a/solutions/articles/79000136321

Applicable to models:  

System S, System S6, System S10, LIA 0608HWCF MS , LIA 0911HWCF MS,  LI 2M, LI 8AS, LI 8ASL, LI 8AS SAL, LI 8MS, LI 8MSR, LI 9AS, LI 9ASH, LI 9AS SAL, LI 9TE, LI 9TEL, LI 9TES, LI 9TU, LI 11AS, LI 11ASH, LI 11ASR, LI 11AS SAL, LI 11ME, LI 11MER, LI 11MS, LI 11MSR, LI 11TE, LI 11TEL, LI 11TER+, LI 11TES, LI 12TU, LI 15TE, LI 16AS, LI 16ASH, LI 16ASR, LI 16AS SAL, LI 16TE, LI 16TEL, LI 16TER+, LI 16TES, LI 20AS, LI 20AS SAL, LI 20TE, LI 20TEL, LI 20TES, LI 22HS, LI 24AS, LI 24AS SAL, LI 24TE, LI 24TEL, LI 24TES, LI 26HS, LI 28AS, LI 28AS SAL, LI 28TE, LI 28TEL, LI 28TES, LI 40AS, LIH 10TE, LIH 22TE, LIH 26TE, LIK 8ME, LIK 8MER, LIK 8TE, LIK 8TEL, LIK 8TES, LIK 12TU, LIKI 14TE, LA 6MR, LA 6S-TU, LA 6S-TUR, LA 6TU, LA 8AS, LA 8MR, LA 8PMS, LA 9K, LA 9PS, LA 9S-TU, LA 9S-TUR, LA 9TU, LA 10MR, LA 11AS, LA 11ASR, LA 11K, LA 11MAS, LA 11MS, LA 11MSR, LA 11PS, LA 11TAS, LA 12PS, LA 12S-TU, LA 12S-TUR, LA 12TR, LA 12TU, LA 13K, LA 14PMS, LA 15K, LA 16AS, LA 16ASR, LA 16MAS, LA 16MS, LA 16TAS, LA 16TR, LA 17PS, LA 17TU, LA 18I-MU, LA 18PS, LA 18S-TU, LA 18S-TUR, LA 20AS, LA 22HS, LA 22PS, LA 22TBS, LA 24AS, LA 25TU, LA 25TU-2, LA 26HS, LA 26PS, LA 28AS, LA 28TBS, LA 33TBS, LA 35TUR+, LA 40AS, LA 40TU, LA 40TU-2, LA 60TU, LA 60TU-2, LA 60TUR+, LA60STU, LA60STUR, LAC 12TR, LAC 16TR, LAJ 11MUR, LAJ 16MUR, LAJ 60TUR+, LAK 10M, LAK 10MR, System M, LAK 3IMR, LAK 6IMR, LAK 9IMR, LAK 14IMR, LAK 14ITR, LAW 6IMR, LAW 9IMR, LAW 14IMR, LAW 14ITR, LIA 7IM, LIA 9IM, LIA 12IM, LIA 14IM, LIA 16IM,LSA60TUR,LSA60TPR,LSA60TPR2,LSA100TUR, SI 5BS, SI 5CS, SI 5ME, SI 5MER, SI 5MS, SI 5MSR, SI 5TE, SI 5US, SI 5USR, SI 6TU, SI 7BS, SI 7CS, SI 7KS, SI 7ME, SI 7MER, SI 7MS, SI 7MSR, SI 7TE, SI 7US, SI 7USR, SI 8MR, SI 8TU, SI 9BS, SI 9CS, SI 9KS, SI 9ME, SI 9MER, SI 9MS, SI 9MSR, SI 9TE, SI 9US, SI 9USR, SI 10MER, SI 10MR, SI 11BS, SI 11CS, SI 11KMS, SI 11KS, SI 11ME, SI 11MER, SI 11MS, SI 11MSR, SI 11TE, SI 11TU, SI 11US, SI 11USR, SI 12TR, SI 14BS, SI 14CS, SI 14KS, SI 14ME, SI 14MS, SI 14TE, SI 14TR, SI 14TU, SI 14US, SI 14USR, SI 16KMS, SI 16TR, SI 17BS, SI 17CS, SI 17TE, SI 18TU, SI 20TR, SI 21CS, SI 21TE, SI 22TU, SI 24TE, SI 26TU, SI 30CS, SI 30TE, SI 30TER+, SI 35TU, SI 35TUR, SI 37TE, SI 40HS, SI 50TE, SI 50TU, SI 50TUR, SI 50ZS, SI 70CS, SI 70TUR, SI 75TE, SI 75TER+, SI 75TU, SI 75ZS, SI 75ZSR, SI 90TU, SI 100TE, SI 100ZS, SI 130TE, SI 130TU, SI 130TUR+, SI 130ZS, SIH 6ME, SIH 6TE, SIH 9ME, SIH 9TE, SIH 11ME, SIH 11TE, SIH 20TE, SIH 40TE, SIH 90TU, SIHJ 90TU, SIJ 10MER, SIJ 75TER+, SIJ 130TUR+, SIK 6TES, SIK 7TE, SIK 7TE-2, SIK 8TES, SIK 9TE, SIK 9TE-2, SIK 11ME, SIK 11TE, SIK 11TE-2, SIK 11TES, SIK 14TE, SIK 14TE-2, SIK 14TES, SIK 16ME, SIKH 6TE, SIKH 9ME, SIKH 9TE, SIW 6MU, SIW 6TES, SIW 6TU, SIW 8MU, SIW 8TES, SIW 8TU , SIW 11MU, SIW 11TES, SIW 11TU, WI 9CS, WI 9ME, WI 9TE, WI 10TU, WI 14CS, WI 14ME, WI 14TE, WI 14TU, WI 18CS, WI 18TE, WI 18TU, WI 22CS, WI 22TE, WI 22TU, WI 27CS, WI 27TE, WI 35TU, WI 40CS, WI 45TU, WI 50TU, WI 65TU, WI 90CS, WI 95TU, WI 100TU, WI 120TU, WI 140TUR+, WI 180TU, WIH 120TU, WPM 2006plus (H), WPM 2006plus (L), WPM 2006R, WPM ACU, WPM Basetec, WPM Econ5, WPM Econ5Plus, WPM Econ5S, WPM EconPlus, WPM EconPlus-E, WPM Econ SOL, WPMJ ACU, WPMJ EconPlus, WPMJ EconPlus-MD, WPM PK, RTCFM, RTCSM