back flow on a cdi compact

[Richie_77]

Recently fitted a fitted a WB cdi compact then notice that it was trying to fire up when there was a fluctuation in the cold main pressure.
Am i right in thinking that i'm going to need a small expansion vessel between the non return and the boiler on the c/m???????????

 

[Mike Jackson]

Yes. DC will stop boiler firing but then you need the vessel to take up expansion of heated water.

 

[Richie_77]

So what there saying is that the expansion is happening within the c/m fair enough ( much like in small instantaneous water heaters if the distance is great enough) but in new builds with combis all new houses have to have non return protection on the incoming c/m dont think ive ever had to fit an expansion vessel in one of those maybe i should of........

 

[plumber0808]

Most manufacturers do recommend you fit them if water meters are fitted

 

[AWheating]

and with some you can have problems with plastic parts failing in the boiler. tbh on new builds you find alot of things that should be done, not done (scale reducers, pressure reducers, check valves, isolators). If the meters in the road its not normally an issue, but if the meters in the property then one (exp ves) should be fitted. They can be expensive for what they are.

 

[vern]

Recently fitted a fitted a WB cdi compact then notice that it was trying to fire up when there was a fluctuation in the cold main pressure.
Am i right in thinking that i'm going to need a small expansion vessel between the non return and the boiler on the c/m???????????

Richie this can be taken care of via the internal software settings, no need to fit anything, are you GSR? If so I will post how to do it

 

[plumber0808]

Richie this can be taken care of via the internal software settings, no need to fit anything, are you GSR? If so I will post how to do it

Disable it? How does it work if one is required? Could you pm me the details of that please vern

 

[vern]

Disable it? How does it work if one is required? Could you pm me the details of that please vern

Lol nothing is disabled, more tweaked, these boilers are incredibly clever on the software / settings etc, some of which are not in the book for good reason

 

[plumber0808]

Thanks for the pm

 

[Richie_77]

hi Vern I've PMd you with my details would love to know how to sort this out electronically I'm kinda guessing you somehow make the sensors less sensitive?

 

[josh]

I'm also intrigued, don't spose you could share with me aswell?

 

[vern]

I'm also intrigued, don't spose you could share with me aswell?

Not on this public forum......if moved i will post up, its no great secret i just dont want custards messsing

 

[josh]

That's fair enough,
i'll stick to the check valve and expansion vessel way!