Inadequate Circulator Pump?

[JC22024]

Is the boiler firing or not with that temp of 89.5C?

Those temps were taken whilst the heating was running can't remember exactly if the boiler was firing at that exact moment but the temp would be fairly consistent in any case.

 

[John.g]

I think the max boiler setpoint temp on that boiler is 75C or maybe just 80C max?. Can you ensure that the pump is pumping away from the boiler and what is the power showing there, it looks like 13W? What is the boiler stat set to? there is a 28mm? copper elbow under the boiler stat, is that the vent?.

 

[JC22024]

I think the max boiler setpoint temp on that boiler is 75C or maybe just 80C max?. Can you ensure that the pump is pumping away from the boiler and what is the power showing there, it looks like 13W? What is the boiler stat set to? there is a 28mm? copper elbow under the boiler stat, is that the vent?.

Yes pump is on outlet and arrow pointing away from boiler.

Not sure why the reading appeared so high yesterday. After upstairs running a few hours checked now and boiler outlet high 70s. yes open vent at top rear right.

Ps just thinking I did actually turn boiler stat down since last night!

 

[John.g]

Thanks, that very high temp of 89C might cause the pump to cavitate and cause circulation problems, might try a SP of ~ 70C for tomorrow and see what the pump power is. Can you see what that power reading was above, looks like 13W to me.

 

[JC22024]

Thanks, that very high temp of 89C might cause the pump to cavitate and cause circulation problems, might try a SP of ~ 70C for tomorrow and see what the pump power is. Can you see what that power reading was above, looks like 13W to me.

Thanks yes I was wondering the same thing last night and turned the temp down a little. Will turn down some more too to hit 70 as you suggest.

The wilo pump is still in there and I'll likely just put the Trident pump in next so can't see the pump power readings any more at the moment.

 

[John.g]

OK thanks again, can see tomorrow what the 70C does, if anything, you will soon know as the boiler dT will decrease if the pump is circulating more.

 

[JC22024]

OK thanks again, can see tomorrow what the 70C does, if anything, you will soon know as the boiler dT will decrease if the pump is circulating more.

Thanks I did turn it down more this morning and ran for 1.5 hrs before I left for work on downstairs zone. Didn't appear to make a difference on the rads not heating decently. Indeed they felt cooler. But will be sure to test this with new pump also incase the boiler is actually boiling the water at high settings! Which it could well be too adding to problems.

 

[John.g]

Presume boiler only ran continuously for 20 minutes or so and then started cycling??.

 

[JC22024]

Presume boiler only ran continuously for 20 minutes or so and then started cycling??.

Correct yes. I did get the olives etc this morning and DHL delivered new pump. So I'll fit it tonight when home from work, refill and properly time the boiler start up run time on GF zone. And see if the rads perform better. Fingers crossed!

 

[JC22024]

System draining down, this is the water coming out (I believe the system shouldn't have blockages. Water is always clean coming out)

 

[JC22024]

Pretty good difference comparing pump to pump opening

 

[John.g]

Is there much of a build up on the Wilo impeller vanes??. or is that the Alpha?.

 

[ShaunCorbs]

Note it will be brown / black this is normal

 

[John.g]

Here's mine, after 18 years, ready to be reinstalled when my smart pump packs up.

 

[John.g]

The impeller on JCs old (alpha/wilo) looks as if it has been in contact with something metallic as it seems a bit chewed up.

 

[JC22024]

The impeller on JCs old (alpha/wilo) looks as if it has been in contact with something metallic as it seems a bit chewed up.

I tried to split the Grundfos but it was the motor coming apart! So didn't want to break it altogether.

From what I can see the old vane looks OK?

 

[JC22024]

PS regards fitting new pump could the gate valves I have be considered a restriction?



They narrow to 15mm or so at pump inlet. Maybe this is nothing to worry about but If there may be a better way of connecting it let me know.

 

[ShaunCorbs]

No there all the same sorry to say you can pipe straight to the pump but then there’s no valves

 

[JC22024]

Well the new pump appears to be working very well.

Boiler only on 20 mins and already can audibly hear the pipes clicking as they heat up in far room of house! Radiator that never heated is already heating up evenly.

Will let it fully warm up for next hour or so and see how it's doing but appears very promising 😀

 

[John.g]

What pump setting? and what are boiler flow/return temps as flow rate can be calculated from this.