Keston C90 User manual

Users Instructions For C90

and C110 Models

The Gas Safety (Installation And Use) Regulations: 1996 (as amended) impose certain statutory

obligations on gas users. Further information regarding these regulations can be obtained from your

Gas Supplier.

All gas appliances must be installed by competent persons by law in accordance with these

regulations. Membership of CORGI is indication of such a competent person with regard to gas

installation.

It is in your interests, and that of safety, to ensure that the appliance is installed correctly and that the

law is complied with. Failure to do so could lead to a hazardous &/or potentially dangerous situation.

Introduction

These instructions should be carefully read to ensure safe and economical

use of your boiler.

The Keston C90 and C110 are high efficiency central heating condensing

boilers designed to provide central heating and indirect sanitary hot water

supply. They are designed for use with fully pumped systems only. The C90

and C110 models are supplied for natural gas use only.

Servicing

To ensure continual safe and efficient operation of the boiler it is

recommended that the appliance be checked and serviced as necessary at

regular intervals. Generally once per year will be sufficient. It is the law that

any servicing must be carried out by a competent person.

NB: There are no user serviceable parts inside the boiler cabinet. The

cabinet should only be removed by a qualified competent person.

Clearances

If fixtures are to positioned close to the boiler the following minimum

clearances must be observed: Top : 350 mm, Bottom : 150 mm, Left : 25 mm,

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Right : 25 mm & Front : 305 mm. Extended clearance is required to the front

to allow for access for servicing.

Cleaning

Normal casing cleaning only requires dusting with a dry cloth. To remove

more stubborn marks wipe with a damp cloth and finish with a dry cloth.

Boiler Setup

1) Check that the gas supply from the gas meter is turned ON

2) Switch on the electric supply to the boiler and controls and set the heating

controls to call for heat.

To Light The Boiler

The C90 and C110 boilers incorporate dual thermostats to allow two different zones

to be connected to operate at two different temperatures. Generally the central

heating zone is connected to zone 1 and the DHW calorifier to zone 2. You should

ask your installer to advise whether your boiler serves one or two zones.

To set thermostat temperatures you must turn the relevant knob to the required

position. As you turn the knob both the displays, one for each module, will change to

either “c nn” or “d nn”, depending on the knob being turned. As the knob is turned the

required temperature (the last two digits of the displays) change. Set the knob to the

position which gives the required temperature. When the knob is released the

display, after a few seconds, will return to normal.

If the boiler detects whether zone requires heat the following sequence will occur:

1) The fan and pump will start inside the module and the displays will indicate “1

nn” to show the boiler modules have started the first stage of the ignition

sequence.

2) After 5 seconds the displays will change to “2 nn” to indicate the spark ignition

of the sequence has started.

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3) After 3 seconds the displays will change to “3 nn” for zone 1 and “4 nn” for

zone 2, to show the module is now alight. NG Zone 2 will be served by the left

hand module only. A demand from zone 2 will only therefore be displayed on

the upper display. If both zones call at the same time then Zone 1 will be

served by the right hand module only until such time as the left hand module

is released by zone 2.

4) The boiler will adjust the output to best match the demands of the system.

The last two digits of the display will continuously show the relevant module

temperature. The module control will allow the temperature to overshoot the

setting by up to 5 degrees before shutting down. The standard display codes

are as follows:

0 nn Module in standby as no heat request from either zone

1 nn Module commencing ignition sequence

2 nn Module generating spark ignition

3 nn Module burning for zone 1

4 nn Module burning for zone 2

5 nn Temporary mode whilst module adjusts its internal settings

6 nn Burner off because required temperature has been reached

7 nn Module at end of heat request from zone 1

8 nn Module at end of heat request from zone 2

A nn Temporary mode whilst module adjusts its internal settings

9 nn Module off due to unexpected problem. The module will attempt

to re-fire from this mode. In this mode the display will alternately

flash “9 nn” and “b xx” where the “xx” has the following meaning:

b 18 Module ran too hot, > 95

C flow temperature

b 19 Module ran too hot, > 95

C return temperature

b 24 Module circulating in reverse. Check external pump

b 25 Module rising in temperature too quickly. Check for

system blockages

b 26 Low water pressure. Top up system pressure and check

for leaks.

b 28 No signal from fan, possible stuck fan motor.

b 29 Fan running when not required.

b 30 Circulation too slow. Check system for blockages

b 65 Waiting for fan to start. Possibly stuck.

All of the above displays, up to “A nn” indicate normal module operation. Display “9

nn” indicates a delay in module operation but will not stop module operation.

Precautions

Care must be taken at all times to ensure that no blockage or obstruction is present

in the condensate drainage line. In addition the air intake and flue exhaust terminals

of the appliance must be free of obstruction at all times.

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Frost Protection

The C90 and C110 have an integral frost protection thermostat. However, care

should also be taken to ensure that any exposed pipework is adequately insulated to

prevent freezing.

Error Codes

In the event of a fault causing a module shutdown the display will show an error

message “E nn”.

Low water pressureE 44 Return thermistor open circuit - check/replace connections/thermistorE 37 Flow thermistor open circuit - check/replace connections/thermistorE 36 Return thermistor short circuit - check/replace connections/thermistorE 32 Flow thermistor short circuit - check/replace connections/thermistorE 31 Difference between flow and return temperatures too high. Check circulation.E 30 Flow temperature increased too quickly. Check water circulation.E 25 Maximum return temperature exceeded. Check circulation.E 19 Flow overheat - check water circulationE 18 Thermal fuse blown or flue overheat thermostat activated.E 12 Internal electronics error - rest or replace control boxE 11 Power has been reset whilst module was in lockoutE 04 Gas valve faulty or not connectedE 03