E8 — Over temperature

The temperature inside the unit has risen too high.

What does fault E8 mean?

The temperature inside the unit has risen too high.

How is fault E8 cleared?

Wait a few minutes for the unit to cool.
Improve ventilation and keep it out of direct sunlight.
If it returns, compare the pump power with the model rating.

To clear a fault, press the Cancel key on the main screen.

Notes from the manual

This fault clears by itself once the unit has cooled.

Which model is right for the pump?

Several HYDROSET PM821 faults appear when the unit's rating does not match the pump's nameplate current. The table below gives the right model for each pump current.

Model selection table
Pump current	Pump power	Model	Typical use
up to 8 A	up to 1.5 kW	PM821-8	1–4 floors, homes and shops
8 – 16 A	up to 3 kW	PM821-16	5–10 floors, booster sets
up to 25 A	up to 4 hp	PM821-25	Residential, commercial and agricultural

The current on the pump nameplate decides the model, nothing else.

Frequently asked questions

How is a fault cleared?

To clear a fault, press the Cancel key on the main screen.

What does fault E8 mean?

The temperature inside the unit has risen too high.

Does fault E8 clear by itself?

This fault clears by itself once the unit has cooled.

All fault codes HYDROSET PM821 user manual

Last updated: 7 September 2026