Here is the raw form of the query using CTE's. Please tweak it to suit your requirement....I hope this helps

;WITH tblCTE_1

AS

(

SELECT T2.MeterID AS CMeterID, T1.MeterID AS PMeterID, Amount

FROM dbo.T2

LEFT JOIN dbo.T1

ON T2.MeterID = T1.ChildID

),

tblCTE_2 AS

(

SELECT PMeterID, SUM(Amount) AS Amount

FROM tblCTE_1

GROUP BY PMeterID

)

SELECT C1.CMeterID AS MeterID

FROM tblCTE_1 C1

INNER JOIN tblCTE_2 C2

ON C1.CMeterID = C2.PMeterID

WHERE C2.PMeterID IS NOT NULL

AND C1.Amount = C2.Amount -- C1.Amount <> C2.Amount -- in case you want those ID's whose SUM(Amount) do not match