Low
d.45 on Vaillant ecoFIT Pure 425

This is not an error code, but a technical setting that allows you to adjust the temperature at which your heating system starts operating.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Value for the base point of the heating curve

From this model's manual
Verified against the Vaillant/Vaillant Ecofit Pure 412 installation & service manual, page 31.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Press the menu button to enter the diagnostic settingsNavigate to setting d.45 using the plus or minus buttonsAdjust the numerical value to your preferred base temperature and press OK to save

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

Monthly cover means no unexpected bills when your boiler breaks down.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

d.43View →d.47View →

All 129 fault codes on the ecoFIT Pure 425

Seeing a different code? Every code this model can display, in one place.

cond.00d.01d.02d.04d.05d.07d.08d.09d.10d.11d.13d.16d.17d.18d.20d.23d.24d.25d.27d.28d.31d.33d.34d.40d.41d.43d.47d.50d.51d.58d.60d.61d.62d.64d.65d.66d.67d.68d.69d.71d.75d.77d.80d.81d.82d.83d.84d.85d.90d.93d.94D.094d.95d.96D.096F.00F.01F.10F.11F.13F.22F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.76F.77F.83F.85F.87F.88F.89P.00P.01P.02P.03P.06S.01S.02S.03S.04S.05S.06S.07S.08S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.39S.42S.46S.53S.54S.88S.91S.96S.98S.99S.108S.109

Related guides you might find useful

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →