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JamesI, Developer
Category: Home Improvement
Satisfied Customers: 1351
Experience:  I have a portfolio of renovated houses, including DIY projects from installing bathrooms and new heating systems to rewiring.
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Buderus Condensing Boiler 50024/C Installed 24 Aug 2007 -

Resolved Question:

Buderus Condensing Boiler 50024/C Installed 24 Aug 2007 - System flushed, Sentinel cleanser & Inhibitor used on installation. I bought property in Dec 14 and have had boiler serviced in Jan 15 and Mar 16. Boiler believed to have been serviced regularly by previous owners although no reports handed over. I had to have fan replaced end of Mar 16 but other than that, no problems
I now have a problem in that I have only tepid DHW, with a very short burst of hot water if I run tap slowly. However if I run the CH I can get sufficient slow running HW for a shower.
I have boiler emergency cover with Swinton and the Gas Plus service engineer sent by them was here about 10 minutes, took the from off, ran the taps & said it needed a new Heat exchanger as there was probably sludge or blockage in the system.Swinton say I am not covered for that. Having read through installation & user manual I am not convinced that is the problem . There are no error codes flashing and pressing the Menu button shows the letters Pr & a solid tap symbol . This & a temp of 60 shown when menu button is pressed seems to indicate it is in warm start mode. However the display screen shows anything between 40 & 59 when inactive and then increases when I run a tap & the flame signal lights up. The flame continues and I can hear the boiler running , temp increases to 72 visually but the water is tepid with the odd burst of hotter water. Could it be a faulty valve or connection? Would welcome your insight. I am a woman and 68 years old and would really like to get this sorted but I think a new heat exchanger is likely to be expensive? Thanks Carolyn
Submitted: 9 months ago.
Category: Home Improvement
Expert:  JamesI replied 9 months ago.

Good evening Carolyn,

Initially it does sounds like the heat exchanger could be at fault, however this wouldnt give you bursts of hot \ cold water.

I am inclined to think this could be due to a build up of sludge in the system blocking the flow of water etc.

Run the boiler with central heating on and see if the radiators get hot, this goes a long way to prove its not the heat exchanger.


Customer: replied 9 months ago.
Hi James - yes I have run the CH and the radiators get hot quickly and the thermostat works fine to regulate the temperature setting and also initiates the radiators on the timer switch. So what next?
Customer: replied 9 months ago.
Prefer to stay on line unless this is going to cost for another reply. I had mentioned I had run CH in first outline of problem.
Expert:  JamesI replied 9 months ago.

Sorry for the delay in responding.

The majority of cases you would expect to see a fault code if the heat exchanger wasnt working.

Reading the service manual here, on page it explains how to clean the HW exchanger, if this hasnt been done and no improvement noticed I cant see how they can say its the heat exchanger, I ma also more confident after sleeping on this that its not the heat exchanger but most likley the flow regulator.

There are two parts which are far more likely to be at fault (both listed on page )55:

60 DHW flow regulator 78138 61 and DHW flow sensor 78137

Though again if these failed it would generate a fault code, these most certainly would affect how much hot water was produced and regulate the temperature, these components can also be manually bypassed to prove if that is the fault, so I would be included to call the engineer back, get him to show you the fault on the heat exchanger which is causing 'erratic' behaviour, secondly ask him to bypass the sensor and see if the fault clears, then do the same with the regulator.


Customer: replied 9 months ago.
Thanks James that sounds more like it. I will go back to them & see what they say. Carolyn
Expert:  JamesI replied 9 months ago.

No problem Carolyn,

It appears the link didnt work, the service manual for your boiler can be found here.

Appreciate if you can rate the service received, and I will await to hear back from you.

JamesI and other Home Improvement Specialists are ready to help you
Customer: replied 9 months ago.
Hi James - update : I gave challenged my insurer and I am waiting for my insurer to respond with what action they will agree to . Hope to hear tomorrow so will let you know before I close case. Thanks for your suggestions.
Carolyn Blanch

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