Any ideas? Unreliable heating.

[garyevans]

This was the old pump. Was mostly on second speed but more recently 3. View attachment 79992

This is what the pump was doing as I switched HW off.

 

[John.g]

I'd say speed 3 was running at; at least a 5M head, can you check the direction of flow on the UPS3, if your system is something like the attachment, then the arrow on the pump should be pointing downwards.

 

[garyevans]

I'd say speed 3 was running at; at least a 5M head, can you check the direction of flow on the UPS3, if your system is something like the attachment, then the arrow on the pump should be pointing downwards.

The pump was upside down so the picture I sent is after I have rotated it

 

[garyevans]

The pump was upside down so the picture I sent is after I have rotated it

Where is the arrow?

 

[John.g]

The pump was upside down so the picture I sent is after I have rotated it

What do you mean by upside down? the pump label etc may be upside down but all that matters is that the arrow on the pump body is pointing in the correct direction.
Your picture is only darkness.

 

[John.g]

Where is the arrow?

On the pump body, will send photo.

 

[garyevans]

What do you mean by upside down? the pump label etc may be upside down but all that matters is that the arrow on the pump body is pointing in the correct direction.
Your picture is only darkness.

The picture of the old pump (blue) is rotated. The writing on it was upside down. It was the pump installed when the house was built.

 

[John.g]

Just to the left of the cable socket, on the pump body.

 

[garyevans]

Just to the left of the cable socket, on the pump body.

View attachment 79997

Yes, it is pointing downward

 

[John.g]

So, are you absolutely certain that the new pump is pumping in the same direction as the old one, ie, the arrow on the old pump was also pointing downwards??, Is you system as I showed above or can you post a photo of it?, its strange that you are getting problems at CP2 even though it is a bit high so CP1 may sort out the problem, was that system chemically cleaned or anything like that between pump changes?.