Potterton Assure E317 / 162 fault code: wrong electrical frequency

E317 / 162 on a Potterton Assure is listed by the manufacturer as “Wrong power supply electrical frequency (Hz)”. The boiler has detected an electrical rhythm outside the range it expects and has stopped as a protective response.

The message does not tell you that the electricity network is definitely at fault, and it does not identify a failed part inside the boiler. It tells the attending professional what the boiler detected at the time of the shutdown.

What electrical frequency means in plain English

The electricity supplied to a boiler alternates in a repeating cycle. Frequency is the number of those cycles each second and is measured in hertz, or Hz. The boiler’s electronics are designed to work with a supply whose frequency remains within an accepted range.

When the Potterton Assure detects a different frequency, it may not be able to control its operation reliably. Instead of attempting to continue, it records E317 / 162 and stops.

Why does the code contain two numbers?

The manufacturer presents the fault as E317 / 162 for this family of boilers. Depending on the display and service information, one or both parts may be shown or recorded. Take a photo and write down exactly what appears rather than shortening the code.

Do not assume that any “162” fault on another manufacturer’s boiler has the same meaning. Fault numbers are specific to the model family and its documentation.

Which Potterton Assure models are covered?

The current manufacturer fault table places Potterton Assure Combi and System boilers in the model group that uses this E317 / 162 meaning. A combi supplies hot water directly, while a system boiler normally works with a separate cylinder, but both listed Assure types can use the same code description.

Check the model name from accessible paperwork or the outside label. If you have a different Potterton product, its own instructions take priority.

What might happen when E317 / 162 appears?

The boiler may stop providing heating, hot water or both. The display may remain on the fault or return to it soon after the boiler restarts. Useful things to remember include:

• whether there had just been a power cut or brief interruption;
• whether lights flickered or clocks reset elsewhere;
• whether the fault appeared during normal mains operation;
• whether a generator, inverter or battery system was supplying the property; and
• whether electrical or boiler work had recently been completed.

These details help build a timeline. They do not prove whether the issue is inside the appliance, in the local electrical installation or outside the property.

How is frequency different from voltage?

Frequency is the rate of the alternating electrical cycle. Voltage is a different electrical measurement. The same manufacturer table lists E385 / 165 separately as an under-voltage fault, so E317 / 162 should not be casually described as “low power”.

There is no safe reason for a homeowner to measure either value at the boiler. Mains testing, wiring and internal electronics require appropriate training and equipment.

What can you check safely?

Photograph the fault

Record the complete display, including any symbols and any second code that appears. Note whether the code is permanent or only appears when the boiler tries to start.

Note known power events

If there was a reported power interruption, record roughly when it happened and whether E317 / 162 appeared immediately afterwards. Do not assume the fault will clear simply because power has returned.

Observe other equipment

Without opening anything, note whether lights flickered or plug-in appliances reset at the same time. If nothing else was affected, that is also useful information. Neither observation identifies the cause by itself.

Tell the engineer about alternative power

If the property was using a generator, inverter, home battery or temporary supply, mention it when booking. Do not alter its settings, wiring or connections to try to satisfy the boiler.

Follow only the exact reset instructions

Find the user guide for your exact Potterton Assure. If it permits a reset, make one attempt once the normal power supply is stable. If E317 / 162 returns, leave the boiler stopped and arrange professional attention.

What should remain off limits?

• Do not take off the boiler cover.
• Do not touch internal wiring, plugs, connectors or circuit boards.
• Do not open the consumer unit or replace protective devices to clear the code.
• Do not use a multimeter or other test equipment on the mains supply.
• Do not adjust generator, inverter or battery settings.
• Do not keep resetting the appliance.

If there is smoke, sparking, unusual heat, a burning smell, damaged electrical equipment or water near electrics, keep clear. Use the normal accessible isolation switch only if it is safe, then contact qualified help. If you smell gas, leave the property and call the National Gas Emergency Service on 0800 111 999.

How an engineer approaches the fault

A Gas Safe registered boiler engineer can inspect the appliance safely, review its recorded faults and test how it responds to the electrical supply. The aim is to establish whether the boiler is receiving an unsuitable supply or is incorrectly interpreting a suitable one.

No responsible conclusion can be drawn from the code alone. If testing points beyond the appliance, the next step may involve a qualified electrician or the appropriate electricity-network contact. That decision should follow evidence, not an assumption based on the words “power supply”.

Information worth having ready

Give the engineer the full Potterton Assure model, the exact code, the time it appeared and which services stopped. Include any known power interruption, visible flickering, reset clocks, recent electrical work and use of temporary or alternative power.

Do not delay the booking while trying to collect every detail. A clear photo of the display and a simple description of what happened are enough to start.

Quick answers

What does Potterton E317 / 162 mean?

It means the Potterton Assure has detected the wrong power-supply electrical frequency in hertz.

Does the code prove there is a network problem?

No. It does not prove whether the issue is outside the property, in the installation or within the boiler.

Is this the same as under voltage?

No. Under voltage is separately listed as E385 / 165 for this model group.

Can I reset E317 / 162?

Follow the exact model guide. If one reset is permitted, try it once after normal power is stable and stop if the fault returns.

Who should investigate it?

Start with a qualified Gas Safe boiler engineer. Testing may show that an electrician or electricity-network contact is also required.