D
Dotty
For hints, tips and secrets of boiler breakdowns.
Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws
W
Whyme
Posted before but if you have a glowworm cxi and the fan pulses on and off along with the display after working on it ...get a hairdryer and heat up the pcb because theres a dodgy capacitor on the board that freaks out when cold......i thought tech were winding me up but it works. (if it doesnt the pcb's knacked).
W
Whyme
Fit a vailant 937 recently and when the cold tap was turned on the boiler pump would kick in but not fire, like if a hot tap had been opened briefly...apparantly the aquasensor picks up negative pressure sometimes even through the cold so..get to the diagnostics by pressing the i + - buttons simultaneously. To access the second level diagnostic codes scroll through to D.97 press the i button scroll to 17. Press and hold the i button untill it returns to D.97. Then you wil be able to access second level diagnostics.....D.88 (adjust the sensitivity of the aqau sensor for water hammer..0=1.5l/min and no delay..1=3.7l/min with 2s delay........i adjusted with a delay, Good times..
N
neily01
Vokera Unicas and mynute he fault code 73 return thermistor faulty. The return thermistor will have corroded because the silly clip holding the flue thermostat to the conveyor has cracked the conveyor. New conveyor and thermistor easy enough done.
R
R1CKY
If you've narrowed down a fault to two suspect components, the faulty one will be the one you choose not to order.
Strange intermittent fault on an Ideal Icos/Isar/Istore? Check the rear of the heat exchanger, they tend to melt and can play buggery with the wiring loom.
Ferolli Modena 102 and similar firing up for seconds at a time with NO DEMAND is caused by faulty thermistors usually. Doing the same with demand, is usually caused by the venturi failing. DO NOT REMOVE unless you are 100% sure or have a replacement, 9 times out of 10 it will turn to a little pile of dust as soon as you touch it!
Ariston Microgenus, usually give a fault code relating to the air pressure switch, most of the time its the fan. They seem to be running perfectly, but they slow down with age and don't spin fast enough to operate the APS.
Strange intermittent fault on an Ideal Icos/Isar/Istore? Check the rear of the heat exchanger, they tend to melt and can play buggery with the wiring loom.
Ferolli Modena 102 and similar firing up for seconds at a time with NO DEMAND is caused by faulty thermistors usually. Doing the same with demand, is usually caused by the venturi failing. DO NOT REMOVE unless you are 100% sure or have a replacement, 9 times out of 10 it will turn to a little pile of dust as soon as you touch it!
Ariston Microgenus, usually give a fault code relating to the air pressure switch, most of the time its the fan. They seem to be running perfectly, but they slow down with age and don't spin fast enough to operate the APS.
N
neily01
N
neily01
Not quite the same but will go with it,poor hw with gled hill 2000 keep pressing sw2 button at the top of pcb until hw temp value is being read. If it reads h85 and the plate is cold then new hw thermistor required.
W
Whyme
N
neily01
Sorry missed that vaillant water pressure switches detect system pressure but also look for a 0.3 bar spike when the pump first kicks in, if it doesn't detect the spike thinks its a pump failure. So if the pumps running but getting f75 it's a blocked up pressure sensor. Bad position on the old models bottom left now top left on the new models.
R
R1CKY
Ahh Gledhill! If you are ever unfortunate to come across a Gledhill Gulfstream, turn around and walk away! I'd rather try and resolve the North Korea crisis that work on one of those abortions!
DHW diaphragm on a Gionnani diverter valve not making contact with the microswitch, bit of plumbers mait and a 5p coin stuck to the top hat on the pin works as great temporary fix until you can make a permanent repair.
Heatline Vizo and similar. Hot water not working will most likely be caused by the diverter cartridge leaking into the motor. Turn the power off at the mains before you touch it, as they can blow fuses on the board, sometime the board itself, when they are moved with water in them.
DHW diaphragm on a Gionnani diverter valve not making contact with the microswitch, bit of plumbers mait and a 5p coin stuck to the top hat on the pin works as great temporary fix until you can make a permanent repair.
Heatline Vizo and similar. Hot water not working will most likely be caused by the diverter cartridge leaking into the motor. Turn the power off at the mains before you touch it, as they can blow fuses on the board, sometime the board itself, when they are moved with water in them.
D
Dotty
Changing one of these on Monday. Vaillant also say there is a filter that can be accessed and cleaned if you remove the rubber flow hose.
W
Whyme
if its an old one the part will be on the bottom left in the brass block "rubber hose type". ifs its newer it will be behind the air exhaust to the left just before the pipe goes into the main heat ex " copper connections no rubber hoses"...its a black part that has a little pin plug attached..if you undo the rubber flow hose then make sure youve got a jubilee clip to make good after. (just crunch the hoses croppie to get rid of the crap around the system).
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