faulty pump maybe ?

[johnh66]

Hi All,

I think the pump on the heating system is bust but not sure. The symptoms are the rads at the end of the line are not getting warm . 2 of the rads taken off and flushed through made no difference at all and when flushed they were not clogged at all. 2 years ago I did a full drain and used sentinel 400 running for 4 weeks and full drain again then added sentinel 100 to protect. Also have attempted to rebalance the entire system which took days to no avail. Then I did the love tap on the pump and all rads worked for about 2 weeks but now back to 3 not heating . The pump is also noisy on level 2 and very noisy on level 3 its a grunfos usd 15.50 type red possibly 12 years old at a guess. Any tips and advice would be greatly appreciated.
John

 

[ScottishGasMan]

It could be gone. The noise it makes, it could be Air or the Bearing/Impellor. What does it sound like. At 12ish years old, it certainly wont hurt to replace it (use a 15-60 then you can turn it down a bit if you need to )

If yor turn the working rads off, to the end ones heat ok? and last question, is the system sealed (you fill it with a filling valve) or open (header tank in loft with ball cock keeping system full)?

 

[johnh66]

Hi,

open system header tank in loft and working OK ,is not dry. The noise from the pump is like a low pitch rumble tried to bleed and no air just a dribble of clear water. If I turn off the other rads yes ish the other ones start to work. There is also a motorized valve for ch and water . The water one failed 2 yrs ago and was replaced when it failed there was no hot water at all. So I'm thinking if the valve was suspect there would be no heating at all which is not the case. Also when putting valve into manual mode ie hooking over the clip there is no difference still same 3 rads cold. Also forgot to say system is micro bore prone to sludge and blocks but given the love tap worked for a couple of weeks on the pump probably not blocked . Time to get the spanners out an other odd thing is pump runs all the time and has done since moving in 5 years ago so could be a part of pump wear...possible board fault on baxi solo 2.

 

[ScottishGasMan]

Certainly could be, the solo's were bad for that fault, although as it controls the boiler saftey yourd Need an RGI to replace and test it

. Also is there a bypass valve? If not and pumps running constant its destined to knacker as when its got no route to push the water it will speed up and overheat.

Looks like new pump, if it runs well then get the RGI to test+Replace PCB to stop the new one going the same way (there not built like they used to be)