# AGA hotplate not reaching temperature (mechanical thermostat models)

> AGA hotplate not reaching temperature (mechanical thermostat models): symptoms, likely causes and how a technician diagnoses it. Common AGA issue. Mon–Sun 8:00AM–8:00PM. Call or text 206-427-7323.

Common issue — here is how we diagnose it, which parts are usually involved, and when to call a pro.

**Common** · Professional repair only

## What you will notice

- Boiling plate will not boil / simmer plate too cool or too hot
- One hotplate works, the other does not
- Hotplate cycles at the wrong temperature

## What is usually behind it

- Liquid-filled control thermostat failed or out of calibration (most common)
- Manually resettable overheat thermostat tripped (common)
- Element failure (one of the three internal circuits) (common)
- Rotary control switch failure (less common)

## How a technician diagnoses it

1. R7 hotplate targets: boiling plate 340 °C / 644 °F, simmer plate 240 °C / 464 °F.
2. Access: remove the four chrome buttons and stay nuts, lift the top plate and prop it with hob support bars (AE4M280399).
3. The rotary control switch, control thermostat and overheat thermostat are located behind the front plate area; both hotplate element plates have manually resettable overheat thermostats that switch the neutral side.
4. Check the thermostat phial location — a displaced phial causes wrong-temperature symptoms with a good thermostat.
5. Simmer spot behaviour is normal-by-design: the 200W element runs permanently while the 2100W element cycles on the thermostat.

## Parts usually needed

- [AGA boiling plate thermostat (liquid-filled)](https://aga.repair/aga-boiling-plate-thermostat-replacement) (control)
- [AGA simmer plate thermostat (liquid-filled)](https://aga.repair/aga-simmer-plate-thermostat-replacement) (control)
- [AGA hotplate overheat cut-out (manually resettable)](https://aga.repair/aga-overheat-cutout-replacement) (safety)
- [AGA boiling / simmer plate element](https://aga.repair/aga-hotplate-element-replacement) (heating)

## Appliances affected

- [AGA Classic 39" Dual Control](https://aga.repair/aga-classic-dual-control-repair)
- [AGA Classic R7](https://aga.repair/aga-classic-r7-repair)

> ⚠️ **Safety & DIY disclaimer:** guides on this site are for information only. Appliance repair involves 240V electricity, gas connections, refrigerant and heavy cast-iron parts — anything you do yourself is at your own risk and can damage the appliance or cause injury. The safe option is to book a qualified technician.

## Related AGA problems

- [AGA oven door rope seal worn — heat loss, poor cooking, hot fascia](https://aga.repair/aga-door-rope-seal)
- [AGA oven or hotplate element failed (no heat / reduced heat)](https://aga.repair/aga-element-open)
- [AGA full power time-out (codes 010–014) — zone too slow to reach temperature](https://aga.repair/aga-full-power-timeout)

## Frequently asked questions

### Can I fix this myself?

Professional repair only. This fault involves gas or 240V electrical components — diagnosis and repair should be done by a licensed technician.

### How much does it cost to fix this issue?

Every visit starts with diagnostics and a written estimate — the diagnostic fee applies toward your repair when you proceed. We never start work without your approval.

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## Book a repair

- Call or text: 206-427-7323 (Mon–Sun 8:00AM–8:00PM, Pacific Time)
- Book online: https://aga.repair/contact/
- Email: service@aga.repair
- Service at your home across the Seattle–Tacoma metro, WA. Diagnostic fee applies toward your repair.

Independent service company — not affiliated with or authorized by AGA / AGA Rangemaster (Middleby). We repair out-of-warranty AGA appliances.