After getting my air-con working well by a valve to cut off the hot water to the heater box it decided that it would lose all of the refrigerant even after refilling.My local A/C bloke reckoned it needed a new heater box-DISASTER.Took it to Kelvedon for a service and Pat found that the A/C pipe junction box just above the heater box was leaking-problem solved for a fraction of what it could have cost.Worth checking if A/C is leaking.
Are you saying your mod caused it?
If not, I’ve always like the idea of it, a picture would be great.
Ian