new pump problem

[dave1973]

Hello all have replaced like for like a grundfos 15-60 pump as the old one was noisey and not pumping to full capacity, also half the down stairs rads where not working although upstairs if ok. Some partical blockage we think. The problem now is it over pumps through the f and e tanks and never did this before , it has and air seperater fitted and the system and drained and filled up perfect today. Any suggestions on why this problem has now occurred!thanks
Dave

 

[twgas]

pump set too high or partial blockage in air seperator

 

[gasacs]

Have you fitted the pump in the right way ?

 

[dave1973]

will remove air seperater tomorrow and replace with new, the over pump does slow down when set to 1. A bit puzzled why it could be blocked as it has been drained twice today can only think on last fill up sludge ect from f and e has blocked up feed port to air seperater. Any thoughts??thanks
Dave

 

[dave1973]

pump definetly fitted the right way and upstairs heating circut is working better than before although the rads down stairs are still slow to warm up and three are not working have checked all manual rad valves on them!

 

[twgas]

a gradual build up of hardened sludge is more likely than crud from f &e tank

 

[dave1973]

cheers mick for info , still puzzled why one minute is was ok and a s soon a new pump exactly the same and set at the varies speeds its happend and it filled up no problems with no slow venting of rads!!

 

[cowley]

You say you have replaced with 15/60 are you sure you didn't have a 15/50 pump before as 15/60 is higher head usually fitted in combi

 

[dave1973]

pump was the same 15-60 grundfos although the 15-50 there not too much difference same loads. Anyhow changed the air seperator and work spot now! could see anything wrong with the old one. The only thing I have changed was the feed pipe tight next to the outlet port on the seperater as to the manufactures drawings although the previous feed was within the 150mm of the vent. Weird one just glad its working.cheer all