avanta plus 28c problem

[powervan man]

Just fitted a Remeha avanta plus 28c and when cold tap is opened the boiler sometimes fires up momentarily for hot water ,remeha have told me to fit a check valve and shock arrester on main supply into the boiler .Anybody else had to do this ?

 

[aggis]

Makesure you haven't any dead legs in the hot & cold, especially if you've taken out the hot water cylinder. Remove the pipes or fit compression caps & crack open to vent air.
You can fit a check valve on cold to boiler but don't forget the mini expansion vessel, but check for dead legs 1st.

 

[diamondgas]

Makesure you haven't any dead legs in the hot & cold, especially if you've taken out the hot water cylinder. Remove the pipes or fit compression caps & crack open to vent air.
You can fit a check valve on cold to boiler but don't forget the mini expansion vessel, but check for dead legs 1st.

Like de ja vu aggis .. lol

 

[powervan man]

There is a 70mm stub with a soldered cap on the tee that was the draw off from the hot water cylinder,and there is also an existing small stub about 100mm long on the rising main just above the stopcock could this be the cause ?

 

[Billy Bob Bob]

There is a 70mm stub with a soldered cap on the tee that was the draw off from the hot water cylinder
​yep,theres your dead leg,remove sweated cap fit a compression one turn water on,carefully vent dead leg,problem solved

 

[diamondgas]

Or better still get rid of the stubbs all together 😛unk:

 

[powervan man]

There is a 70mm stub with a soldered cap on the tee that was the draw off from the hot water cylinder
​yep,theres your dead leg,remove sweated cap fit a compression one turn water on,carefully vent dead leg,problem solved

Okay cheers will try that ,i've fitted loads of these and never had it before but this is the first one where i've fitted a prv on the incoming main so i wondered if that was causing the problem .

 

[diamondgas]

Okay cheers will try that ,i've fitted loads of these and never had it before but this is the first one where i've fitted a prv on the incoming main so i wondered if that was causing the problem .

Something to remember for the future powervan man is to alow for expansion if you fit any form of shut off valve downstream of the main stopcock. I'd advise you deffo fit a expansion vessel (shock absorber)... Usual path for expansion is back down the mains but a PRV will stop that facility!

 

[powervan man]

Something to remember for the future powervan man is to alow for expansion if you fit any form of shut off valve downstream of the main stopcock. I'd advise you deffo fit a expansion vessel (shock absorber)... Usual path for expansion is back down the mains but a PRV will stop that facility!

Okay but do you think this lack of expansion is causing my boiler problem, or the fact that there is a very short dead leg on the hot outlet pipework ?

 

[diamondgas]

short dead leg deffo I'd say ...

 

[boblydon]

I have fitted loads of advanta's, have you checked the incoming mains pressure to the boiler???, also what is the cold water flow rate?????, you may also need to fitted a pressure reducing valve on the mains cold water.

bob