How to test a Fan in a Gas Boiler. Gas Training how to test a fan is a gas combi boiler. Boiler repair training. Ideal logic boiler faults. #Plumber #Gas-Engineer
Over the last 16 years I have been on Vaillant, Worcester ,Ferroli, and Baxi training courses. Although I have learnt something every time there are always engineers at different stages of knowledge, so you never seem to get to the technical end of the fault finding. IE testing the different gas valves,fans, pumps, pcb’s relay’s capacitors and so on. We have to try and diagnose faults on all make and models, which is sometimes frustrating and can be costly when making a wrong decision. I probably have a £1000 worth of parts in my cupboard that I diagnosed wrong over the years (I’m not to proud to admit that). These videos have been a god send. it’s much easier when you see the videos rather than reading from the manuals. Not sure how you find the time but thank you Alan, ideal engineer, heating geek, tomcat and all the other engineers that I have found on u tube willing to share there knowledge. As you have said in the past Alan, it’s a lonely trade fault finding. sometimes very rewarding and a nightmare on others. Shame these ideal videos are coming to an end. .
Thanks. Just to add some value, as many are confused by the zero/negative pressure gas valves. A *zero/negative pressure* gas valve. When the outlet of the gas valve is at atmospheric pressure it is *off* - no gas passes through. When pressure at the outlet is detected that is below atmospheric, it opens. The valve does this by sensing pressures - mechanically, not electrically. The fan creates that negative pressure on its negative (inlet) side. The other side of the fan is positive pressure. Well actually it is a _compressor,_ as it compresses premixed gas and air sending it to a burner, but manufacturers retain the name fan. The more the pressure is _negative,_ (the faster the compressor turns) the more the gas valve opens allowing more gas to pass through the valve into the mixing chamber, mixing with air, then to the burner. It *must* sense a _negative_ pressure before it can open. So, the faster the fan turns the more gas is drawn into the mixing chamber, as the more the gas valve opens. This gradual opening of the gas valve is all by pressure on its outlet port, not electrics. There are no electrical proving switches to detect the compressor (fan) is operating. The negative pressure on the outlet of the gas valve proves that the combustion fan is running, so no electrical _fan switches_ are needed. The gas valve contains an electric solenoid to ensure the gas is permanently off when the compressor (fan) is not turning. Usually in the centre of the air entry port of the compressor (fan) is a small venturi just above the gas valve, so the effect of the rushing air sucks gas from the gas valve which is mixed with air in the mixing chamber just before the compressor (fan). The mix is not a perfect air-gas mix (stoichiometric), have excess air to prevent sooting. The gas-air ratio is normally adjusted in the gas valve, so more or less gas is sucked by this venturi effect, making the air/gas mix richer or leaner. Most manufacturers just ask for the CO2 in the flue gasses to be checked then the air/gas ratio adjusted to achieve specification - which is different for all manufacturers. Some ask for you to set fan speeds with some asking to monitor differential pressure and additionally at the same time check CO2 for both max and min settings. Some manufacturers are confident that they have set it all correctly as it left the factory and don't even want it monitored. But the main principle is that the venturi effect at the inlet of the compressor (fan) ensures a slightly leaner than stoichiometric mix. So, the burner is fed a stoichiometric mix which is ignited as it is blasted into the combustion chamber. The speed of the compressor (fan) essentially determines the size of the flame - the higher the speed the more gas is sucked in to be premixed. The lower the speed the less gas is drawn in. This is full burner modulation. Makers have been R&Ding the variables in all this setup having some compressors (fans), gas valves, and burners sucking a very low volume of gas, allowing boilers to modulate at lower kW rates.
There’s something about learning from guys who are actually on the job rather than a training centre that makes it more realistic. The mix of both types of videos help so much. Thanks mr ideal. Hopefully you reconsider.
Mr ideal man your videos have got to be best on this channel. Helped me loads so thanks from me. Hopefully see some more from you in future. Allen great content mate, keeps getting better and better. Thanks mate
Great video straight forward on the tools training .. shame it's the last one .. Helped me out on the ideal boilers testing fans the right way .. Thanks Mr Ideal
Really appreciate your videos mr ideal I work on these boilers everyday so the testing you do is brilliant and really helps hopefully you can change your mind and make more videos
Allen, you are a very rare person in that you explain things really clearly and don't confuse the novice engineer. I have just learnt from you PWM - an acronym I knew the wording of from my solar panel mucking about but had no idea what it meant technically. If you don't run a school for engineers then you really could, and it would be very successful. I paid £3000 for a Gas Safe course and it barely touched on the mechanics and fault finding of boilers, let alone such advanced stuff as PWM. Thank you SO much for your help.
Mr Ideal, Thank you so much for this video and for clearly explaining how PWM controls the fan and pump speeds. Your job title may not include the word 'trainer' but you are a great teacher. Thank you again.
just watched this video, on 1st January 2023, happy new year all, and Allen, your doing a fab job and thank you to the gentleman that made this video, it was really good and helped me understand better about how a positive fan pressure zero governer works to push the air/gas ration into the heat exchanger and how the pwm plays its part in modulating. god bless you all !!
I could listen to Mr. Ideal all day, what a wealth of knowledge. I don't think Roy would mind sharing the stage with Mr. Ideal, I actually think it would benefit us more. Roy doing the Baxi and Mr. Ideal doing the Ideal. That's sorted then, looking forward to your next video Mr. Ideal.
Thankyou Mr Ideal for all your time ,effort and really informative videos. I wouldn't worry about the fact that your not a trainer, your videos are easily as good as anything I have ever had on any manufacturers training day, hope you reconsider at some point. Cheers. :-)
Personally like him and Roy. Would like to see more of his videos too. No harm in all the videos. Really enjoy them all and some helpful material. Hopefully he continues to do them. It's appreciated. Thanks everyone.
Mr Ideal thanks for sharing your knowledge great video very well explained I agree Roys agreat trainer but I believe you are also gifted in sharing your obvoius skill and experience, I wish you good health for the future thank you once again also thanks Allen for providing the platform for this to happen all the best Rob
Thanks for your great videos mate wish that guy the best I spotted some of his videos and he might say he's not a trainer but have learnt so much on testing ideal boilers What a great human being and a credit to the gas game Make sure you take him for a pint when the jailer frees us from lockdown 🖖
Fantastic thank you for sharing. Actually something which will be useful to all. Its takes a lot of time to put these videos together therefore thank you for making the time and educating us all. Amazing stuff and actually well put together to Mr Ideal.
Mr ideal, thank you so much for the information you have shared it’s been very much appreciated. Top man. I mainly work on Baxi and vaillants but the contract I’m working on they have started fitting logic combi c30’s so it’s a good heads up on how to check bits in the future. Again thank you and all the best👍
Thats great, its a good help for me ,working on these boilers alot im diffinetly gonna have a look next time im servicing one. but a big thanks to you for you time
Good video, like having operational engineers viewpoint as you are sharing your experience, not just focussing on the topic and those additional background comments are full of information.
Mr Ideal, thanks for the video's, you shouldn't worry about not being a trainer, you got the information across well, it's not easy making videos I wouldn't know were to start. It's always good to someone else explanation of how things work, field experience is always good to pass on especially to those of us that don't get to work on may of these boilers .thanks again
You all probably dont give a damn but does anybody know a trick to log back into an instagram account..? I was dumb forgot my login password. I would love any help you can offer me.
@Melvin Reuben i really appreciate your reply. I got to the site on google and I'm trying it out atm. Looks like it's gonna take quite some time so I will get back to you later when my account password hopefully is recovered.
Sorry to see you go mate I think it’s good to see other engineers take on boilers, I’ve sent some in to Allen but obviously no where near the level you are, they are very informative and have helped me immensely 👍🏻
Absolutely amazingly good content & presentation. With very limited insight or videos on modern boilers PWM available, this is one of the best👍👍 With the limited time & so much to cover it is tough. It would’ve been good if there was more time to cover the Fan PCB Halls sensor & some details of the fan’s On-board components. Thanks Mr Ideal & thanks Allen.
Mr Ideal...genius....been looking for some videos like this for a long time. Sorry to hear your going, but thanks for your vids. If Allen or anyone else can point me in the right direction or provide links to watch more of your vids then I would be extremely grateful. All the best 👍
Yes a real shame mr ideal was a great help shame the boiler manufacturers dont do more like this too help out the breakdown boys like myself as it's good to watch the videos a few time so it sinks in. Good luck and let's hope he returns at a later date .
I love watching gas and HVACR videos 😀👍🌱 for interest and to learn how it works. I like that the board just sends the low voltage PWM signal and the fan does all the hard work,I guess that means less likely for PCB to break and suffer thermal stress!
The fan on my own Logic Heat 18 sometimes whistles, and sometimes doesn't. Since I put the Ideal weather comp kit on, it runs at lower demand and is quieter.....at least that's my impression. I've checked all the flue seals but have never got to the bottom of the whistling as it's borderline acceptable anyway. It's on now and not whistling...typical 😊 Many thanks Mr Ideal Engineer and best wishes to you.
Thank you very much. I am an electrician but I don’t know about boilers, more computers and valve amplifiers. Just watched your video and having noted what each connector was took them off and cleaned them. My boiler now works again. Although I think my pocket wishes it was still faulty! Anyway thanks again. Oh well. It worked till I turned off the hit tap. When I turned it on again it failed again. The fan shudders for a second when powered on.
Hi -- thanks for your top videos -- iv'e been a gas engineer for 47 years and been to many Ideal Logics + many other condenscing boilers with fan problems + but to be honest iv'e never fully undertood the wireing to the fans -- i've always known there was a permanent 240 volt ac supply + a pcb on the fan but not known the voltages of the dc wires -- one thing i've known + other engineers too is be careful when you diconnect the fan on removal when servicing -- coz a few times when its been reconnected its blown when re -testing the boiler !! -- and thats been with always dis-connecting with the power fully off to the boiler ! -- i think its better trying to remove the fan with the 240 vlt permanent supply still connected !! -- i know care is needed . but the wires are normally long enough to remove it still connected -- thanks for shareing your knowledge -- JIM