Recent: Safely remove screen protector from a Macbook Air?

Mend > Home Heating Systems

Mend Honeywell CM921 Thermostat Boiler Wireless

Programming Honeywell CM921?

Hi: The heating engineer installed this unit during installation of a new boiler. This is a 1 day wireless programmer. Unfortunately, I am finding it quite difficult to program this unit as the Honeywell user guide is quite complicated.

Can you please help me by providing a simple step by step guide to program this unit eg: heating twice daily, keeping the heating on 24/7 when weather is very cold etc. The unit is connected to an IDEAL combi boiler.

Our system is a bit different as we also have a hotwater storage tank connected to the heating system ie hot water is supplied to the tank via the CH system. There are to valves, installed underneath the boiler, which we have to open to start heating and then shut these to provide hot water in the storage tank.

With our old room thermostat it was easy because we were able to set the heating on " tiwice daily" which automatically supplied the hot water. During the summer, we could the the same but with the two vales shut so that hot water got supplied tothe storage tank. Our bathroom & shower unit are supplied with hot water via the storage tank.

I do hope I have manged to explain properly.

Tan
August 2010
I have had one of these programmers installed today and what i can make of it is you programme time against temperature.

So i have mine set at 21deg from 3pm then at 11pm i have it set for 17deg.

So during the day and night when we dont need a lot of heat the boiler will not fire unless it drops below the set temp.Between 3 & 11 the boiler fires unless its warm anyway.

ChrisK
January 2011

Automatic Answer

We may have found other answers which could help you.

Click here for Thermostat Boiler Wireless

Related Questions ...

Mend heating thermostat wireless
1

home heating systems?

We have a Worcester Bosch RD532 boiler but no thermostat. Which wireless thermostat would be best suited to th... [Read more]
Mend thermostat boiler wall
1

my rdh10rf siemans thermostat will not send signal to my boiler. ?

Both the wall unit and the wireless control panel are on and all the lights are on but it is not communicating... [Read more]
Mend thermostat boiler wireless
2

how do i reset my wireless thermostat?

Lights on the thermostat receiver linked to boiler both gone out. Sender part still working fine so am assumi... [Read more]
Mend Siemens Thermostat Wireless
1

Siemens RCR10/433 receivers?

I am in a recently acquired house and am new to all these wireless systems. I have looked at all the previous ... [Read more]
Mend thermostat wireless heating
1

How do I reset my wireless Siemens RDJ10RF thermostat?

"I have a wirelss Siemens RDJ10RF thrmostat with RCR10/433 receiver.""The lights on the receiver have gone out... [Read more]
Mend reset power start
1

Please could anyone tel me why my boiler constantly shows err 501. I reset?

Sometimes reset works, sometimes one has to power off and start again. This has been happening many times over... [Read more]
Mend vaillant boiler error
1

Boiler Vaillant 824e turbomax ?

central heating has stopped working. it was connected with wireless thermostat, intially i thought something i... [Read more]
Mend heating hot water
2

Vokera HE35 has no heating but have hot water, how can I fix this?

Our boiler is not working properly on return from holiday we found we can only get hit water & no heating. I'... [Read more]
Mend heating thermostat programmable
1

Boiler firing up when room stat is not calling for heat?

Hello, Hope someone can help? I've had a sales wireless programmable thermostat installed and when tested b... [Read more]
Mend boiler thermostat heating system
1

GREENSTAR 28i junior\iflo digistat scr\drayton rf601 not keeping temp?

I have a greenstar 28i junior boiler connected to a iflo digistat scr which connects via wireless to remote dr... [Read more]
Mend vaillant ecotec fault code
4

Vaillant Ecotec plus 824 with no central heating?

Please help!! We've been in this house for almost a year - so I'm not sure when the boiler was installed bu... [Read more]
Mend combi boiler central heating thermostat
1

baxi combi, my radiators are on all of the time all of a sudden?

the electric blew in our house and later on i noticed the rads in the house were on constantly. I have a Bax... [Read more]
Mend thermostat heating wireless
1

Drayton Digitstat RF1 Wireless Thermostat?

Have come home from an extended holiday to find no heating. Stat set at 15c to come on when house cold. Stat s... [Read more]
Mend thermostat 50 boiler
1

Which Wireless Thermostat do I buy for a Ferroli Econcept 50 | Gas Boiler?

We have a one year old Ferroli Econcept 50 | Gas Boiler and want to have a wireless thermostat fitted. Can you... [Read more]
Mend boiler thermostat heating
1

Problem with Siemens RDJ10RF boiler control?

I have just had a new combi boiler fitted with a Siemens RDJ10RF wireless control/thermostat. Everything works... [Read more]

How to mend ...

Find out how to mend just about anything howtomendit.com for free repair help, information and advice.
Mend Home Heating Systems ...