CH pump location

I now see why the pump is presently located (rather awkwardly) in the boiler casing!...the expansion tank water level is presently 2.48m above the pump...if I put the pump in the loft it reduces down to 1.28m - clearly not enough. I can't really move the expansion tank any higher and there is not much area around the boiler siting for a pump to be fitted at a lower level.

I have searched for a conventional boiler with an integral pump...Keston Celsius 25...but that requires an expansion tank height from the top of boiler to its (tank's) bottom of 2.75m minimum, plus it would require the vent pipe to be relocated off the flow pipe to the return.

Are there any other good quality conventional boilers with integral pumps without such demanding configuration requirements?...failing all, I may have to locate the pump below the floor in a room on one of the leg runs...I don't know if this is acceptable as many boiler schematics show it to be placed in the run from the boiler to the vent pipe on the flow line - Any advice much appreciated.

In your situation the flow and return probably come out of the top of the boiler, so can you not stick it on the return just above the boiler? Or is there not space inside the casing (regular boilers sometimes have a load of air inside them) to take the return pipe down to the pipe and then back up to the return of the boiler at the top.

I recomend a Buderus 600 XXR. XX is 11 or 19 or 24 depending on your whole house boiler size calculation.

This boiler wil fit under a kitchen worktop but flue would be illegal if there is a window just above as I said before, so you'll need an off duty fireman or electrician to commission it, there are plenty who believe themselves competent to do so.

Paul Barker said:

In your situation the flow and return probably come out of the top of the boiler, so can you not stick it on the return just above the boiler? Or is there not space inside the casing (regular boilers sometimes have a load of air inside them) to take the return pipe down to the pipe and then back up to the return of the boiler at the top.

I recomend a Buderus 600 XXR. XX is 11 or 19 or 24 depending on your whole house boiler size calculation.

This boiler wil fit under a kitchen worktop but flue would be illegal if there is a window just above as I said before, so you'll need an off duty fireman or electrician to commission it, there are plenty who believe themselves competent to do so.

Click to expand...

No there is not room above as it will be a wall hung boiler and the expansion tank head height has become an issue thanks to Agile!

I have looked at the Buderus it doesn't appear to have an integral pump, also its dimensions don't allow much room around it for where it is to be situated....Presently I am considering the Viessmann Vitodens 100-compact. Its dimensions allow some space to work with in that I can move it over slightly and have the pump installed vertically along side it by bringing the flow pipe down from it and then back up to the loft thereby just about obtaining the said minimum 2m head to the expansion tank water level (would this be feasibly correct?). Its schematic has the pump on the flow pipe of the boiler before the vent pipe unlike many others that show the pump to be installed after vent pipe...it also doesn't mention anything about relative expansion tank head heights... link if interested -
100-compact

Strange, but MI's are Gospel so go a head.

Paul Barker said:

Strange, but MI's are Gospel so go a head.

Click to expand...

Pardon my ignorance... MI's?

Just to be sure...regarding the positioning of pump vertically alongside bottom end of boiler on flow pipe out of top of boiler to attain adequate head height would be for all practical purposes OK, yes?

Manufacturers intsructions

Yes, but I would do the same in are ee vee ee are ess ee and put it on the return in your sytem at your home.
If it were me at my home despite the beter knowledge and experience of Tony I would try it on the return in the loft first. BUT for me a little extra pipework later and another drain down is commonal garden. Actually I'd get my latest addition to the firm on it, his pipework is better than mine and it's far less effort watching someone else work while you field phone calls to feed them with work.