Can a diverter valve cause these symptoms

[scoobydo123]

I have just changed my circulator to a flowson domestic. This was due to the bolier gurgling and reaching saftey cut out regulary (Prima F60). The change seems to have improved the situation (no cutouts). However during the work I decided to do a flush and have been running the heating to circulate the chemical. I noticed that the rads were not getting hot all around the house. I have let the rads heat up individually and all ok there. It appears that either the new pump is not flowing very well or the diverter valve is not allowing the full flow of the new circulator. The new circulator seems very very quiet. Can a diverter valve be checked/cleaned. System is 10 large radiators and 1 small.

Cheers

 

[reneel]

Is the system balanced properley?? WHat pump did you replace it with..... how much head does it have??

 

[twgas]

Gurgling is usually caused by air, which in turn is caused by a poor design/install, this may have caused abuild up of sludge and so restricting the flow. What was the water like when you changed the pump?

 

[scoobydo123]

Have been round and balanced, pump was the cheapest on the shelf in B&Q. System is 13 years old and has been fine up until last winter where I have been increasingly having to reduce the stat on the boiler. Water condition seemed fine.

Sorry head is approx 750mm

Thanks a lot

 

[reneel]

either there is air in the system (airlock some where) / try venting pump / all air vents / rads etc (make sure any aav' are working properley) - or sludge in the system is blocking off some pipes/rads / or the pump is not powerful enough for all the rads (long shot) - but may be case as all rads heat up individually.......

 

[scoobydo123]

I am suspecting the pump it just seems too quiet. Although it seems to be doing a better job than the old one as the boiler is no longer tripping the over temp stat. But somehow I am also suspecting the diverter valve (mid postion?) where it diverts the flow to either the cylinder or CH. When the other rads were off the rads that were on where piping hot.

The pump that was removed was the original myson CP53 if I remember correctly. Tried to take it apart but for a nose but could not get the impeller out. It was still working but I think it was not pumping very well

 

[reneel]

if the rads are hot when others are off then the system is not correctly balanced. as you say the pump not being powerful enough can cause the same prob (ie rads hot when not all open) - have you got a 3 port valve or 2 x 2 ports?

 

[scoobydo123]

just 1 3 port. After the chemical dosing I screwed down lockshields and just had a couple working at a time.

 

[reneel]

when you turned the lockshields off did you count the no. of turns and re-open at the same amount??

 

[scoobydo123]

No as that were no right (decorating) etc but previously had been more than enough heat at each rad. Started balancing properly using k-probe but seems like not enough flow getting around as I go through each rad


Cheers

 

[reneel]

k-probe? any good? need a good digi thermom myself! - sounds like there could be sludge somewhere in system causing a blockage....

is the pump head (pressure) the same as the old one was????

 

[scoobydo123]

K probe is the type of thermo probe for the multimeter so should be fine. Pump was a cheapy but I have ordered a Grundfos as the cheapy you cannot get the cover back properly and the quick snap terminal blocks dont work and are just wedged in.

 

[reneel]

quick snap terminal blocks??!!! sounds like the pump is poor ..........

 

[scoobydo123]

Guess it is wait for the grundfos to arrive and see what happens. It is uncanely quiet. Hopefully it is the pump and I can then repost and warn people against the pump. It is made by Wilo but not branded as one of theirs. But it is an improvement on my old Myson

 

[kevindgas]

wilo pumps are among the best so

1. check wired up correctly
2. pump is installed correctly? which way is the flow is this correct?
3. when switched on put a large flat screwdriver on center screw and put handle to your ear you will be able to hear the impeller rotating
4. make sure both pump valves are actually open!
5 . pipes either side of pump should get hot within 5 to 10 seconds of each other
6. put system to hot water only does the correct pipe get hot on diverter valve
7. repeat 6. for C/Heating only
8. check for any bleed points in your airing cupboard

finally quick snap terminal on pump - push pins down to open, insert wire and release. the pins are then loose if wires inserted correctly