Viega Manabloc Conundrum

[Adkroot]

I installed a manabloc with their flow-thru (standard) setup and recently discovered that when I shut off the supply for the water heater, which is located at the heater, it shuts off all the water supplies out of the manabloc.

Can anyone help me understand what I’m missing here? Thanks, Daniel

 

[Reach4]

Do you have the big water supply (service) pipe coming in at the bottom?

Are there any tees between the upper right port to the water heater cold inlet? Are there any tees near the water heater?

 

[Sponsor]

 

[Adkroot]

Yes, my water service enters at the bottom of the manabloc exactly as in the picture, and the water supply out and in are also as in the picture. The supply to the water heater is direct - no tees- with just a full port shut off near the heater. When I shut that off I get zero water out of the manabloc to any of the runs.

 

[Jeff H Young]

hooked up wrong

 

[Adkroot]

hooked up wrong

Could you explain? The illustration I included is one of the two recommended approaches to connecting the manabloc. Water service in at the lower port, cold water supply to heater and return from heater at the top two ports. Straight runs to and from the heater with no tees on either length. What could I possibly be missing?

 

[Reach4]

Have water being supplied from the Manablock. Close the supply valve at the bottom but leave the valve at the input to the water heater open. Does the lavatory or tub or kitchen sink still have water under those conditions.

Answer should be no, but something is weird. So this weird test seems justified.

 

[Jeff H Young]

Could you explain? The illustration I included is one of the two recommended approaches to connecting the manabloc. Water service in at the lower port, cold water supply to heater and return from heater at the top two ports. Straight runs to and from the heater with no tees on either length. What could I possibly be missing?

other possibility is the manabloc is defective or you are incorrect about the piping

 

[Adkroot]

Have water being supplied from the Manablock. Close the supply valve at the bottom but leave the valve at the input to the water heater open. Does the lavatory or tub or kitchen sink still have water under those conditions.

Answer should be no, but something is weird. So this weird test seems justified.

I’ve shut off the supply to the manabloc many times to install additional home runs, so I can confirm that with the supply shut off and the valve to the heater open there is no water supplied to any of the fixtures. I agree that something is very weird and I’ll have to check in with Viega on Tuesday to see what they have to say. The only thing that I can possibly conclude is that the water supply to the manifold should enter at the top cold port instead of the bottom port, although they recommend either the top or bottom port for the service entrance.

 

[Jeff H Young]

thermastatic mixing valve at the water heater ? keep us posted to what the problem is its a very simple issue guaranteed