My new Potterton combi condensation boiler makes a loud fast drumming sound, on start up from cold only, for about 30seconds. This is the case for both hot water and central heating demands. After about 30 secs the noise stops and the boiler works normally. If the central heating has been on for a minute or so, any demand for hot water is satisfied without any noise.It seems that the vibration/drumming is caused by the fan rapidly modulating its output up and down causing pressure changes which are then just amplified by the panels. The question therefore is what is causing the fan to modulate? It seems that the boiler controls cannot handle heating up water from cold.If I start the CH/HW with the temperature set at below about 45 degrees there is no noise(I can then increase the temp to say 60 degrees after 30secs without the drumming occurring). The drumming only occurs when starting from cold at temperatures above about 55 degrees.There is no fault code showing. Flue and condensate drain both checked for blockages (there were none).Any pointers would be be very welcome!Many thanks in anticipation.Jerry R
Thoroughly cleaning the system - again! Making sure all air excluded. Opening all radiators. Checking flue for blockage.
Hi, I’m a moderator for this topic and I wonder whether you’re still waiting for an answer. If you are, please let me know and I will do my best to find a Professional to assist you right away. If not, feel free to let me know and I will cancel this question for you. Thank you!
Yes I'm still waiting for an answer, however as I only posed the question last night and it's now still only the morning after I'm not exactly "champing at the bit". A slow correct answer is better than a quick wrong or incomplete one!
Just a couple of pieces of additional information that I thought of:
1. the system has been cleaned and flushed through twice with a proprietry cleaner and then system inhibitor and silencer permanently added.
2. the boiler is still under manufacturer's warranty but I wanted to have a good idea of what the problem is before I contact the manufacturer so I don't get fobbed off (or lose a fortune on their premium cost phone "Help" lines!) - hence my using "Just Answer". The installer insists that he has checked everything and the problem is nothing whatsoever he has done (ie it's a manufacturing fault).
3. I don't have a circuit diagram - and neither am I a heating engineer - but I'm convinced the problem is that whatever inputs control the fan modulation (probably a combination of flow/return water temps mainly - plus any other inputs such as CO/CO2 levels in flue and ambient air temp) is either faulty or incorrectly set. But I could be wrong (I often am!).
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Hi my name is XXXXX XXXXX lets see if we can get you sorted in the shortest possible time. It sounds like the fan bearings - a little off centre. That is why is rattles very slightly until the fan speeds up. I would call the manufacturer and get them to check it (tell them it is noisy) but make sure it is cold when they come. You should not have to pay for their visit.
I Andrew thanks for the answer but it's definitely not the solution. As explained above the noise is not coming FROM the fan - but it is caused BY the fan. Specifically, it is caused by the fan modulating very rapidly at start up in other words the fan speed alters up and down which in turn causes the air pressure in the burner box to increase and decrease which in turn causes the steel panels of the boiler to drum/vibrate loudly. The question is - what is causing the fan speed to go up and down rapidly at start up? The fan itself is not overly noisy.
Thank you for your patience, your business is very important to us, we are waiting on the Professional with the right expertise to come online. Feel free to let us know if you would like us to continue searching for an Professional or if you would like us to close your question. Thank you for your understanding!
Hi Walt. Please close this question. On reflection it was a bit unrealistic to expect a simple answer to what is probably a complex issue requiring an expert on site to take various sensor measurements. Thanks anyway