Sealed Heating connected to CWSC

[jaydebruyne]

happy Christmas everyone!!

Came out to a job a couple weeks back to ground floor rads stone cold, 1st floor rads some rads working others not. Checked pump: weak as hell. Replaced the pump and went to top up pressure as the previous gauge had gone so changed that as well. Pressure went up and straight back down. Checked PRV and was fine. Assumed it was a leak somewhere. Nope. Left the filling loop open which fills up the CWSC in the loft.

Have checked vented cylinder connections all are ok. Filling loop mains cold has been connected to the old gravity cold feed to the central heating system.

Where would the obvious points be where the heating and CWSC could be connected? I know there shouldn’t be but are there any obvious things I’m missing if someone has converted an open to a sealed system incorrectly? Seems ok to me though.

I was thinking of putting a NRV on the feed from the CWST???

 

[jaydebruyne]

UPDATE:

The heating is crossed over to the hot water.. ran it and dirty system water coming out.

I’m thinking less invasive and easiest route to take would be to run a new hot supply?? I have a feeling the crossover is in the bathroom to the towel rad as this is the only rad where pipework was amended to relocate the position of the rad when the bathroom was done and they’ve had issues since then. Bathroom floor is tiled.

 

[andyplumber]

if i read this right you fill up the heating via filling loop connected to circs and the cold water storage tank fills up if that the case most likely cracked coil mixing heating and hot water

 

[jaydebruyne]

if i read this right you fill up the heating via filling loop connected to circs and the cold water storage tank fills up if that the case most likely cracked coil mixing heating and hot water

Jesus I didn’t think of that, I need to wake up!!!!

 

[ShaunCorbs]

I would say coil or someone's teed into the heating from the hot water

 

[jam1979]

Coil split as the water coming out of the taps is dirty hence new cylinder time