What would cause this to a pump so quickly?

[ashthekid]

A whole new home plumbing system that is less than 2yrs old and consists of UFH both upstairs and downstairs(and a few towel rails) onto a split system Hitachi Yutaki S ASHP.

I had an issue with any heat flow going through to the UFH manifolds and then a leak from the low loss header. The leak looks like it was there for quite some time which would explain the pressure loss over a long period.
Just had the loss header replaced and pump removed. This is what the pump looked like.

 

What would cause such a state after so little time? That is not sludge inside, it is rock hard!

 

No inhibitor? Miscalculated inhibitor, the leak, some kind of chemical reaction….?

 

[Conor]

That looks like corrosion. Combination of no inhibitor and a leak that's been letting oxygen in. Combine that with high temperatures, and things corrode very quickly. You'll need to a do a full power flush of your system.

[sharpener]

If it is rock hard I would use a chemical cleaner e.g. citric acid based descaler that you leave in for 3 days while the system is running, then flush and neutralise. Better chance of getting it clean than just short term mechanical flushing even with a cleaning agent.

[SteamyTea]

16 hours ago, ashthekid said:

some kind of chemical reaction

Well it is certainly that.

 

Are you in a very hard water area?

[ashthekid]

Yes, very hard water here. I have a water softener but obviously not used or hooked up to to this part of the system. 
 

I just pray this hasn’t spread to the heat pump itself. 

Edited November 29, 2024 by ashthekid

[sharpener]

2 hours ago, ashthekid said:

Yes, very hard water here. I have a water softener but obviously not used or hooked up to to this part of the system. 

 

Worth getting it tested e.g. Adey or Fernox tests. Your HP installer/servicer should be able to do this.

 

Possibly you would be better to fill the primary system with the softened water, provided the pH is not too low. Vaillant specify quite a narrow range, and definitely on the alkaline side of neutral "If the value is below 8.2 or above 10.0, clean the installation and treat the heating water.".