Gas Engineers Will Require CPA1 From 1st April 2012
Flue gas analysers are essential for heating professionals to use when working with heating appliances. From April 2012, gas engineers who do not hold the CPA1 will have their CEN1 and/or HTR1 suspended.
During the past 10 years, gas analysers have become a vital part of every heating professionals’ tool kit. Today’s electronic instruments are multifunction in their operation, enabling gas escape detection, temperature, pressure and carbon monoxide (CO) environmental monitoring as well as analysis of flue gases. These functions can help to assist in completing forms such as landlord certificates, gas safety certificates and Benchmark commissioning checklists.
Due to recent changes in the building regulations, there are now over 7.8 million high efficiency appliances installed in the United Kingdom with a further 1.5 million being fitted each year. These changes have made it more important to use a flue gas analyser as part of the day-to-day working practice of a heating professional.
The Gas Safe Register announced just under a year ago that all registered gas engineers who have or due to gain ACS modules CEN1 or HTR1 now require the flue gas analyser qualification CPA1. Those gas engineers who do not hold the CPA1 qualification after 1st April 2012 will have their CEN1 and/or HTR1 suspended.
British Standards such as BS 6798, BS 7967 and BS 5871 Part 1 state the requirement to use a flue gas analyser when maintaining and servicing particular heating appliances. The CPA1 Combustion Performance Analysis of Domestic Appliances assessment is intended to provide gas engineers with the essential knowledge of correctly using a flue gas analyser.
There are numerous professional instruments on sale, which are made by several different manufacturers that include Kane, Telegan, Testo and TPI but heating professionals should select an instrument that is capable of measuring all combustion gases and appropriate pressures to make sure that a heating appliance is working safely and efficiently.
Monitoring the products of combustion will ensure a heating professional has the ability to precisely control levels of carbon monoxide (CO), oxygen (O2), the ratio of carbon monoxide and carbon dioxide (CO/CO2), excess air and flue gas temperature.
When testing a gas installation for soundness, many instruments have the facility to measure pressure enabling a let by/tightness test. The temperatures of flow and return water can also be monitored using a suitably equipped flue gas analyser making commissioning of a heating appliance considerably easier.
Another unique feature of today’s professional instrument is to monitor ambient carbon monoxide levels that will inform the heating professional as to the amount of CO at each given minute during a test period.
Smoke Test before using a Flue Gas Analyser
Before commissioning or servicing an oil-fired heating appliance, it is important to perform a smoke test by taking a sample of the flue gases from the boiler flue before using an electronic flue gas analyser. Failing to carry out such a test may result in temporary or permanent damage to the flue gas analyser’s internal components including the oxygen and carbon monoxide sensors.
A smoke test can be accomplished using a smoke test pump and filter paper. To prevent condensation of the flue gases, first warm the smoke test pump body. To obtain a sample of flue gas, insert a clean piece of filter paper into the smoke test pump slot and tighten the clamp.
Take a Sample of the Flue Gases
After the heating appliance has been operating for approximately ten minutes, place the sampling tube of the pump into the test point on the heating appliance flue whilst been careful not to make contact with the internal surfaces of it. This could cause carbon deposits (soot) to enter the sampling tube and produce a smoke spot that provides an incorrect reading.
Check the Smoke Count
Pump the smoke test pump evenly ten times to obtain a sample of the flue gases through the filter paper. Remove the filter paper and compare the smoke spot produced on the filter paper with the smoke count chart provided with the pump. Adjust the burner’s air damper so a smoke count of no more than two is obtained and repeat the test until the desired result is achieved.
Water Vapour Present
If the air damper on the burner is opened excessively then this may produce a wet spot on the filter paper. This wet spot is caused by water vapour within the flue gases that is caused by too much excess air. Simply reduce the amount of air and re-test until there is only a trace or a smoke count of one is achieved.
Consult Manufacturer’s Data
If in the event that the smoke count will not reduce then, if possible, observe the burner flame for instability, misshape or impingement. Recheck the burner’s oil pump pressure against the burner manufacturer’s data and if necessary, replace the burner nozzle with a new burner nozzle to the correct spray angle, flame pattern and output as indicated by the burner manufacturer.
After a satisfactory smoke test, a flue gas analyser can now be used to complete the combustion efficiency testing of the heating appliance.
Electronic Smoke Test Pump
The manual measurement of a smoke count using a smoke test pump, as described above, can be complicated and time consuming. However, with the introduction of the electronic Testo 308, this process has become faster whilst not compromising the accuracy of a smoke test. This instrument will definitely compliment the range of tools, including the flue gas analyser, used by a heating professional in the oil-fired heating appliance industry.