613692
6
Zoom out
Zoom in
Previous page
1/34
Next page
6
Your ST9420C should have been set up to work correctly when it was installed.
However, the following will show you how you can modify your settings to meet
your particular lifestyle.
To assist you with programming and everyday use your ST9420C will display text
messages at every stage to help you get the most out of your central heating and hot
water system. The ST9420C uses LoT™ Technology to constantly update the display
to give you feedback about what is required.
Step 1: Setting the Date & Time
Your ST9420C had the date and time set at the factory, and these are normally
maintained by a backup battery in the event of power failures. If you wish to change
the date or time, or if the LoT™ Display shows the message ‘SET DATE + TIME’ just
follow the instructions below. Otherwise, go to Step 2.
a. Move the slider to the DAY/TIME position. The message ‘SET DATE + TIME’ will
show briefly on the screen, followed by ‘SET THE DAY’, and the day of the month
will now be flashing to indicate it can be changed.
GETTING STARTED WITH YOUR ST9420C
HOT WATER HEATING
DAY/TIME
HOT WATER
HEATING
RUN
using this to calculate the correct time to switch on to reach your comfort temperature,
when you want it. So the times you set are when you want the heating to be at
the correct temperature, and the system adjusts the starting time to meet this.
Delayed Start is an alternative to Optimum Start. It works by using your normal
programmed start times, compares the actual temperature with the set temperature, and
delays the start a little depending on how close these temperatures are to each other.
Optimum Stop saves energy, and money, by switching off a little earlier than the
normal programme time. If the house is up to temperature, you will not notice the
effect on the temperature, but you will see a difference in your fuel bill.
The radiator symbol on ST9420C will flash to let you know whenever Optimisation
is operating.
The other controls in your system should not require adjustment.
CONTROL OF YOUR SYSTEM
6


Need help? Post your question in this forum.

Forumrules
1

Forum

honeywell-st9420c

Reset search

  • Switched heating to off but it remains on. Taken out batteries from thermostat and heating still on Submitted on 31-7-2021 at 20:16

    Reply Report abuse


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Honeywell ST9420C at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Honeywell ST9420C in the language / languages: English as an attachment in your email.

The manual is 1,21 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info