Central Heating Boiler - horizontal distance to expansion

[LoungeLizard]

Question for an expert Central Heating installer:

Does it matter if I move the vertical expansion pipe about 7 feet horizontally from the boiler?

Are there any building regs to say you can't?

All the horizontal & vertical distances are as per boiler instructions; this one isn't specified (just says as close as possible).

Currently, the vertical expansion pipe goes pretty much straight up above the boiler to the expansion tank. But the vertical pipes are in the way and I want to move them down the wall.

[Mudman]

In the absence of 'expert' advise.. I would say that (from experience only) your expansion pipe should take the quickest route to the atmosphere. If the most direct route (ie; vertical) is not an option then you should have the least 'resistance' to vertical.

No 'right angle' bends in the pipework. It really should be 'sweeping' bends only.

As for 'Building Reg's'.. I don't know of any regulations that stipulate a specific route for pressure relief pipework. Providing it follows the basic principals.

[KARL]

In my case the expansion pipe is at the hot water tank which has a (back-up, used mayby 3 times from the beginning) immersion element fitted. At the boiler there is a pressure relief valve to provide emergency venting in case of the gas boiler overheating. The boiler is not even within the house and the system has been running like this for more than 33 years without incident.

[stanleyman]

It is actually a vent pipe, the expansion goes back up the fill pipe. Depending on the layout it doesn't even need to come independantly from the boiler but can be on the flow pipe. If you move the vent pipe horizontally it should have a slight rise to prevent air being trapped in the boiler. Why not convert to a sealed system and do away with the the expansion tank and all the pipes.