I am in the middle of my first ever big plumbing project and all is going well, I can solder pipes and everything 
I would really appreciate a little advice on inverted loops in the hot supply side.
It is in a bungalow. Normal water system, cold tank high in loft, hot water tank on ground floor. The shower pump fitted between joists and is a Salamander RSP100 which is suitable for this application with a few rules. 600mm between bottom of cold tank and pump.
One rule I am struggling to stick to (and dont understand enough to break!) is about inverted loops, you should not have any apparently.
Now, with the hot tank on the ground floor and the pump on the ceiling, the whole system is one big inverted loop?
That aside, I need to have a small inverted loop in the loft to clear a joist (so it is about a 4" high inverted loop). Am I correct in thinking that if you can clear the air lock from the loop on commisioning then it should not cause any ongoing problems?
As I understand the subject, inverted loops are only a real problem for 2 reasons.
1. They can cause headaches for commisioning (to get the water flowing), once sorted they should not cause any further issues under normal circumstances (normal being that no large amounts of air enter the system)
2. If they are big loops (no idea what big is - maybe a couple of feet?) then if the flow is low and air content is high then air can build up in loop until a lock is caused and flow stops.
Am I OK to have a small loop (with a bleed valve to commision) or is it really important not to have any? What about the whole system being one big loop?!
I would really appreciate a little advice on inverted loops in the hot supply side.
It is in a bungalow. Normal water system, cold tank high in loft, hot water tank on ground floor. The shower pump fitted between joists and is a Salamander RSP100 which is suitable for this application with a few rules. 600mm between bottom of cold tank and pump.
One rule I am struggling to stick to (and dont understand enough to break!) is about inverted loops, you should not have any apparently.
Now, with the hot tank on the ground floor and the pump on the ceiling, the whole system is one big inverted loop?
That aside, I need to have a small inverted loop in the loft to clear a joist (so it is about a 4" high inverted loop). Am I correct in thinking that if you can clear the air lock from the loop on commisioning then it should not cause any ongoing problems?
As I understand the subject, inverted loops are only a real problem for 2 reasons.
1. They can cause headaches for commisioning (to get the water flowing), once sorted they should not cause any further issues under normal circumstances (normal being that no large amounts of air enter the system)
2. If they are big loops (no idea what big is - maybe a couple of feet?) then if the flow is low and air content is high then air can build up in loop until a lock is caused and flow stops.
Am I OK to have a small loop (with a bleed valve to commision) or is it really important not to have any? What about the whole system being one big loop?!
