Rehau manifolds installed backward

[Aaron K]

Had a contractor come out today for in-floor heat not working. I have 2 zones each with Rehau manifolds supplied from a single pump and neither zone worked. Contractor felt the pump had failed and replaced it only to discover that the system still did not work. After much consideration, contractor realized that the manifolds had been installed backward and suggested that this is the problem and that this bad installation had led to the pump failing. However, system had been functioning properly for 16 years before this. Contractor wants to replace the manifolds as the next step, but this seems silly to me. Is there contractor's theory rational? Anyone have another idea?

 

[oz-plumber]

So you've had a functioning system for 16 years and now its not working.

The pump was replaced and the system is still not working.
Was the pump ever faulty, did the contractor do any tests on the pump?

Re: Rehau manifolds - like many others of that design, they don't fair well with the flow & return piped backwards.
I doubt they would have operated for 16 years if they were piped in reverse.
I could be wrong.
Does you manifold have flowmeters?

There could be a couple of issues, but if your contractor thinks it the expansion tank - get a new contractor.

Post a couple of pics of the setup - much more helpful

 

[snowhead]

Next step should be a new contractor and not any more new parts without sound reasoning why.

Contractor felt the pump had failed, clearly wasn't a sound reason.