Its certainly not a high dT just now, d.40, would IMO have to reach ~ 75C to flag S.53 so no ideas I'm afraid. Based on the WB fouled PHEX it might indicate that the DHW flow was ~ 4LPM @ 50C with flow/return of 58C/50C.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local