Mike the Boilerman -
Your Gas Safe Registered boiler
and central heating repair technician for
London, Thames Valley and south coast
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The Potterton Flamingo is the last really simple and basic, old-fashioned format wall-hung boiler produced by Potterton before the drive for increased fuel efficiency really took hold. It has a traditional cast iron heat exchanger, a permanent pilot light with a conventional thermocouple, and that’s about it. Very simple and very little to go wrong. Some versions have an overheat thermostat which makes them suitable for sealed systems (i.e. with no header tank). The Flamingo comes in both balanced flue (through the wall) and conventional flue (vertical chimney) versions. The balanced flue version is room-sealed which means it draws its combustion air in through the same hole in the wall as the flue exits from and the combustion chamber is sealed off from the house atmosphere. This is fundamentally safer than the chimney flue version as any noxious fumes under fault conditions cannot enter the living space. This does not apply to the chimney flue version. Neither version of Flamingo has a flue fan, which on more complex boilers is a common fail point.
If your Flamingo won’t light and you’d like me to visit to it, get in touch. Call, text or WhatApp me on 07866 766364.
What to check if your Potterton Flamingo stops working:
1) The pilot light. This is the No 1 fault on these. Pull the front off the boiler and look inside to see if the pilot flame is present. If no flame, this will be why it doesn’t work and it needs lighting. There are instructions on the boiler cover somewhere, but here is a video posted on YouTube showing the method on a Kingfisher boiler, but the method is identical. (Its not my video by the way - it was posted by a chap called Christopher Mahon, to whom I extend my thanks.)
2) Check the heating is set to ON at the programmer or time switch.
3) Check the room thermostat is at a ‘high’ setting.
4) Check the temperature control knob in the boiler is set to a high setting, and not set to OFF. Temperature control knob shown in this photo here, on the far left, calibrated 1, 2, 3, 4, 5, MAX.
5) If your pilot flame was out and you successfully re-lit it, check you remembered to turn the the black control knob the final quarter turn to the ‘flame’ position. This is easy to forget, I know this from experience :) The black control knob can be seen in the photo in 4 above, on the right hand side.
6) On some Flamingos there is an overheat protection thermostat too, which when triggered also shuts off the pilot flame and prevents you from re-lighting it, just as if the thermocouple had failed. This is because the overheat protection thermostat when it trips, interrupts the current from the thermocouple and puts the pilot flame out. (Sometimes the overheat thermostat develops high electrical resistance which has the same effect.) If your Flamingo won’t light, you may need to find the re-set button and press it back in to enable the pilot flame to be re-lit. In the boiler above there is such a button, but annoyingly I forgot to take a photo showing it. Its location is immediately behind the the igniter button and out of view. The igniter button is the black button roughly in the centre of the above photo in 4 above.
If you’ve done all the above with no joy, or if the pilot flame keeps going out, you’ll need a visit from a boiler technician. Call me if you wish on 07866 766364. I’m based in Reading, Berkshire and am happy to travel. You can also text or WhatsApp me on that number.
Common faults on the Potterton Flamingo:
This is the weakness in all boilers with a permanent pilot. The thermocouple is the safety device that turns the gas OFF if the flame goes out. The Thermocouple tip is heated by the pilot flame, the heat creates an electric current which operates an electro-magnetic valve which keeps the gas ON. If the pilot flame goes out for any reason, the thermocouple cools, the electrical current stops and the thermo-electric valve springs closed, shutting off the gas. This also happens when the thermocouple fails, and the user is unable to make the pilot flame stay alight as there is no electrical current. A new thermocouple is needed, which is quick and easy to fit.
Gas valve failure:
The thermoelectric valve in the gas valve is prone to failure resulting in identical symptoms to thermocouple failure above. A new gas valve is usually required.
The temperature control knob is attached to the variable temperature thermostat spindle. This thermostat senses the temperature inside the heat exchanger and occasionally loses its calibration, leading to the boiler heating its water to a higher and higher temperature for a given setting. Eventually as the fault develops, the water in the boiler will begin to actually boil which paradoxically, is the last thing you want your boiler to do. In the short term this can be worked around simply by turning the temperature control to a lower setting, but eventually you will run out of lower settings and a new thermostat will have to be fitted. On Flamingos fitted with an overheat protection thermostat, a boiler with a failing control thermostat will be prevented from boiling by the overheat protection thermostat. It does this by turning OFF the pilot flame, which can lead a repair technician into mis-diagnosing and changing the thermocouple, when the control thermostat failing is the root problem.
This is where the boiler pops and bangs as it heats up, making a noise like an electric kettle approaching boiling. The usual cause is corrosion contamination inside the heat exchanger. Not an important problem and many users elect to just live with it and ignore it. The corrosion can sometimes be removed by power flushing, or ‘boiler quietening’ chemicals can be added to the circulating water. Results are variable and no guarantees of a fix for kettling can be given.
These are about the only problems a basic Flamingo suffers from. If you have one, I suggest you keep it!
If you would like me to repair your Potterton Flamingo, contact me on my mobile 07866 766364
The most common version of the Flamingo is the 50s which looks rather different from the Flamingo photos at the top of this article. Until I serviced one the other day, I’ve not had any photos of the 50s but that all changes now. I took lots of photos of the service (with customer’s permission) so here is a photo-by-photo account of servicing a Potterton Flamingo 50s.
Servicing a Flamingo 50s:
Look through the viewing port to inspect the colour and stability of the pilot flame. Nice blue colour, no yellow, burning steadily with no ‘flame lift’. Note the thermo-couple tip nicely enveloped in the flame.
Now light the main burner and check the same things as above, also known as checking the “flame picture”.
Go outside to inspect the balanced flue terminal. This terminal is a lot larger than a modern boiler terminal as there is no flue fan, the flue gasses leave the boiler by natural convection. Very simple, virtually nothing to go wrong this way.
The light fitting here is closer than it should be and other technicians might classify this as “At Risk”, but the fitting shows no signs of distress so I classify it as “Not to Current Standard”. Pragmatism rules ok!
Remove combustion chamber front panel and brush clean main burner and hoover out loose debris drawn in through air intake.
Extinguish pilot flame and listen for gas valve ‘clunk’ as thermocouple cools and gas valve turns the gas supply off. Should happen in less than 60 seconds.
Inspect heat exchanger gasways for soot or blockage. Clean if necessary. Not necessary in this case, the gasways are perfectly clear.
(This photo is with the camera inside the combustion chamber and looking vertically upwards.)
The flue collector hood. In this case I did not remove it to clean inside as occasionally necessary, as the heat exchanger flueways were immaculately clean, indicating I would find the same under the flue collector hood.
Measuring the burner pressure to ensure it is within the range stated on the boiler data plate.
And that’s about it! After replacing the boiler cover and lower controls cover I ran the boiler up to temperature to check the temperature control thermostat was working correctly, then handed the boiler back to the customer.
Taking the covers off:
The Flamingo 50s in my customer’s kitchen, looking immaculate and well cared for before I start.
Potterton Flamingo, an open flue version. Note the slots in the front for ventilation of the flue. Note also the heat stain on the casing. This is unusual and the result of a mis-placed seal inside this particular boiler, now repaired.
Copyright Michael Bryant 2019
Site first published 16th January 2004
Last updated 24th December 2019
Gas Safe Register 197499, CIPHE registration number 56207