GAS REFERENCE PACKAGE

1 GAS REFERENCE PACKAGE 2010v2 Aim To Pass With Gb-Gas 1 GAS REFERENCE PACKAGE This document is free to download and copy from GAS REFERENCE PACKAGE 2010v2 Aim To Pass With Gb-Gas 2 Combustion See for more details. Visual inspection The main reasons for incomplete combustion 1. Lack of oxygen (soft yellow flames) 2. Incorrect burner pressure (over gassed / under gassed) 3. Flame impingement (flame chilling) A good pre-aerated flame should be bright blue with a strong inner and outer cone, and above all will have a roar.

2 If there is any yellow in the flame then it is incorrect. (Do not mistake yellow for orange, as orange flames are usually dust being burnt.) Procedure for carrying out a service with the aid of a Combustion Analyser. 1. Carry out the service as per manufacturer s instructions Tightness test, clean and inspect. 2. If the appliance is range rated turn to maximum setting Traditional boilers adjust to max burner pressure. Combination boiler on hot water mode or chimney sweep mode. Condensing boilers check manufacturer s instructions.

3 All other appliances burner(s) on full.** **Be aware that checking a eye level grill when the hob burners are on will cause incomplete combustion on the grill. 3. Take flue gas analysis If acceptable: Reset to original burner pressure / gas rate and retest if ok Then conduct: Flue and spillage test Check safety controls. Ventilation. Confirm safe operation If unacceptable: If possible rectify fault(s) then re test If not possible follow the unsafe situations guidelines. At Risk for flued appliances Immediately Dangerous for Flueless appliances.

4 4. Complete job documentation If using a flue gas analyser acceptable readings vary depending on the appliance type. Consult manufacturers instructions. If the manufacturer supplies a Co2 reading only then make sure you are very close to that reading. GAS REFERENCE PACKAGE 2010v2 Aim To Pass With Gb-Gas 3 BS 7967-3 APPLIANCE TYPE CO/CO2 RATIO Back boiler unit Boiler In combination with fire Central heating boiler Hot water circulator Flued space heater (check man instructions) Flueless space heater Water heater flued and Flueless Warm air heater Flueless cooker Oven Hob Visual inspection of flames Grill (CE marked) Grill (No CE mark) Range oven flued Refrigerator (LPG)

5 Tumble drier Flued flueless Gas lights (LPG) Any ratios above these readings maybe through, misuse, lack of maintenance, damage or aging. Make sure the probe is placed correctly: Open flued: centre of the flue, or 200mm inside the draught diverter. Room sealed: From the manufacturers test point or 200mm inside the flue duct from outside Flueless appliances: On the flue outlet using the spreader bar tester. The appliance has run for 5 mins. Monitor the Co reading carefully if this starts rising quickly then remove the tester as you may damage the equipment.

6 If you don t get the reading you are looking for let it run for a further 10 mins and retest. A full clean and check or repair of the appliance is essential and then re-tested. If it is not possible to achieve these levels then the appliance should be regarded as at risk for flued appliances and immediately dangerous for Flueless appliances. COMBUSTION ANALYSER Natural gas 21 COMBUSTION ANALYSIS GAS REFERENCE PACKAGE 2010v2 Aim To Pass With Gb-Gas 4 Carrying out a room test for carbon monoxide with a Combustion Analyser.

7 General 1. Position an open ended sampling probe approximately 2 m above floor level in the centre of the room and at least 1 m away from any suspect appliance installation . 2. Close all external doors, windows and customer adjustable ventilation. 3. Record the level of CO over a 15 min period. If the indoor level of CO starts to rise during this period, check for CO migration from other sources. 4. If there is no rise then proceed to test the appliance. Room sealed and open flued appliances Operate the appliance at full rate until the CO reading stabilizes or begins to fall, whichever occurs first.

8 Cookers Ensure that all permanent ventilation to the space in which the appliance is situated is unobstructed. Place a saucepan on each of the pan-supports above the two largest hotplate burners and put approximately a litre of water in each and cover with a lid. Use a saucepan with a flat base and a base diameter of between 160 mm and 220 mm. Place the grill pan in its highest position under the grill. Open/operate the customer adjustable ventilation in accordance with the cooker manufacturer s instructions, window or extractor fan.

9 Light the grill, oven and the two hotplate burners at their maximum setting. Turn the oven down to gas mark 5 (or mid-range if not calibrated in gas mark numbers). Record the CO levels at 1 min intervals. Turn the hotplate burners down to simmer when the water boils. Turn the grill off after 30 min. If during the test the CO reading: begins to fall without exceeding 30 ppm, stop the test; the installation and cooker are satisfactory; does not exceed 30 ppm for longer than 20 min and begins to fall and does not exceed 90 ppm at any time, stop the test; the installation and cooker are satisfactory; Exceeds 90 ppm at any time, stop the test, ventilate the room, identify the cause, rectify and repeat the test.

10 Flueless water heaters Ensure that all permanent ventilation to the space in which the appliance is situated is unobstructed. Close all customer adjustable ventilation to the space in which the appliance is situated. Light the appliance and operate it at maximum gas rate for 5 min recording the CO levels at 1 min intervals. Flueless space heaters Ensure that all permanent ventilation to the space in which the appliance is situated is unobstructed. Close all customer adjustable ventilation to the space in which the appliance is situated.