boiler pump not strong enough?

[daveeg]

Hi Guys

I went to see a job this week the client said an gas engineer had replaced her boiler over a year ago but it has never worked properly since. This is a large house with 4 floors the 3rd and 4th floor heating is luke warm and never really heats up since new boiler was installed. Apparently the engineer swapped like for like(Keston qudos 28s). over the last year there has been 6 keston engineers and multiple visits from the installer. She called me to see if i could shine light on the situation.

First thing i noticed was the pump head on the keston is 6m but the radiators on top floor measure 9 m.

There is 14 column radiators and a 162 litre cylinder, boiler is in basement so is pumping up with a lot of bends,also only 22mm flow and returns.

Any ideas?

is the boiler powerful enough?
can i install an additional pump?
do they make domestic 9m pumps?

many thanks

david

 

[SimonG]

HWOS do an 8m for about 85 I think it is, just slightly longer than a standard 6m.

 

[daveeg]

do you get problems when running two pumps on the same system? what if the external pump is stronger than the boiler pump will it have a reaction?
thanks for reply

 

[SimonG]

I had to do this on a job not too far away. They added a number of cat iron column rads on a system boiler. Fitted the 8m pump under the boiler, wired from the existing pump and took the impeller out of the internal pump.

Ideally I would have wanted to zone it and have a pump on each zone but the building was over 200 years old and it would have been a nightmare.

 

[Fishpond]

do you get problems when running two pumps on the same system? what if the external pump is stronger than the boiler pump will it have a reaction?
thanks for reply

Use a low loss header to overcome this.