J
john s
Hi gents......be gentle on a first time poster eh?
My company have installed a number of Wolf CGB boilers, either the CGB35 or the CGB50................which as the model number suggests are around 35kw and 50kw output.
Now I recall other threads on this forum suggesting that back up was not "ideal" and I guess this was due to the UK agent changing from Pulsar to Ubink. It does still seem however that some parts can take as much as 2 weeks to appear.
My main issue with these boilers is that the heat exchangers appear to be extremely prone to scale build up. This is not on the water side but is actually combustion side. For those not familiar with the boilers the heat exchanger is formed from an aluminium alloy drum and a finned tube is coiled tightly around the inside of the drum. The flue gases are drawn through the pipe coil and up between the coil and the drum. We have found that the gaps between the finned tube coils, and the gap between the coils and the drum, can become so caked up with scale that it is impossible to clean.
The agents have told us on one occasion that the problem is caused by the boiler running too hot. Run them in a "more condensing" mode and the water generated will wash away the residue that is causing the scale. We have also been advised by the latest agent that perhaps they are producing too much condensate, and it is the drying out of this in the heat exchanger that is causing so much scale....................two completely contrary opinions!
The agent and Wolf claimed there were unaware of what the scale may be so I sent it to a laboratory and they said that over 25% of it was aluminium oxide based..............ie it appears the heat exchanger is eroding and forming the scale in conjunction with combustion products.
So my question is, do any of you guys have similar problems with scaling up of these boilers because all of those we have installed are suffering it and Wolf are suggesting it is because they are not serviced often enough. Apart from the fact this is not the case I would also question whether the design of the heat exchanger makes it impossible to clean the areas that the scale is forming. In fact I pointed out that we have to service more regularly than 12 months since we are generally called out to locking out boilers before the year has elapsed.
I am aware of others who have now stopped installing Wolf because of the back up problems a few years back (the present agents do appear better but some parts are still on 2 week lead) and I am aware of some boilers that have been taken out and replaced after just 2-3 of years of service, so I would really be interested in the first hand experience of others to see if we have been really unlucky.
Most of our installations tend to run for longer hours than your typical domestic installation since they are fitted to indoor pools serving air and water heat exchangers. However the pool environment and chlorine are not a contributory factor since the design prevents the intake of pool room air into the boiler intake and one of the worst cases we have the boilers are 20 metres from the pool room.
Thanks in anticipation of feedback.
John
My company have installed a number of Wolf CGB boilers, either the CGB35 or the CGB50................which as the model number suggests are around 35kw and 50kw output.
Now I recall other threads on this forum suggesting that back up was not "ideal" and I guess this was due to the UK agent changing from Pulsar to Ubink. It does still seem however that some parts can take as much as 2 weeks to appear.
My main issue with these boilers is that the heat exchangers appear to be extremely prone to scale build up. This is not on the water side but is actually combustion side. For those not familiar with the boilers the heat exchanger is formed from an aluminium alloy drum and a finned tube is coiled tightly around the inside of the drum. The flue gases are drawn through the pipe coil and up between the coil and the drum. We have found that the gaps between the finned tube coils, and the gap between the coils and the drum, can become so caked up with scale that it is impossible to clean.
The agents have told us on one occasion that the problem is caused by the boiler running too hot. Run them in a "more condensing" mode and the water generated will wash away the residue that is causing the scale. We have also been advised by the latest agent that perhaps they are producing too much condensate, and it is the drying out of this in the heat exchanger that is causing so much scale....................two completely contrary opinions!
The agent and Wolf claimed there were unaware of what the scale may be so I sent it to a laboratory and they said that over 25% of it was aluminium oxide based..............ie it appears the heat exchanger is eroding and forming the scale in conjunction with combustion products.
So my question is, do any of you guys have similar problems with scaling up of these boilers because all of those we have installed are suffering it and Wolf are suggesting it is because they are not serviced often enough. Apart from the fact this is not the case I would also question whether the design of the heat exchanger makes it impossible to clean the areas that the scale is forming. In fact I pointed out that we have to service more regularly than 12 months since we are generally called out to locking out boilers before the year has elapsed.
I am aware of others who have now stopped installing Wolf because of the back up problems a few years back (the present agents do appear better but some parts are still on 2 week lead) and I am aware of some boilers that have been taken out and replaced after just 2-3 of years of service, so I would really be interested in the first hand experience of others to see if we have been really unlucky.
Most of our installations tend to run for longer hours than your typical domestic installation since they are fitted to indoor pools serving air and water heat exchangers. However the pool environment and chlorine are not a contributory factor since the design prevents the intake of pool room air into the boiler intake and one of the worst cases we have the boilers are 20 metres from the pool room.
Thanks in anticipation of feedback.
John
