Grant Vortex Boiler Fires up when cold water switched on

[FarmerJohn]

Hi,
I have recently had a Grant Vortex Blue 36KW boiler internal fitted and it seems to work OK but I have noticed that when the cold water is switched on, say in the bathroom, the boiler starts up like it is heating up the internal hot water store. It doesn't do it every time, but after it has been left for about an hour it does.

Just wondered if this was normal? If not how would I fix this?

Also I have noticed that the front panel does not want to stay on the boiler on the left-hand side. I think it is the insulation in the panel that is pushing against the expansion tank, it just seems too thick. If I remove the insulation it fits.

Any help would be appreciated.

Regards
FarmerJohn

 

[Deleted member 267285]

I have recently had a Grant Vortex Blue 36KW boiler internal fitted

Just wondered if this was normal? If not how would I fix this?

No it’s not normal, and 1st port of call is get your installer back. It could be crossed pipes or a dead leg.

 

[BoilerBob]

Yup dead leg somewhere. Bob

 

[FarmerJohn]

Hi,
Many thanks for the replies. Just read about Dead legs and it was the first I had heard of them.

There are indeed a number of pipes that have no flow as they were put there for future use and are currently capped off. There are at least a 3m length in both the hot and cold pipes and both are 22mm.

In addition, there is one more 15mm pipe about 2m in length which will be removed very shortly. Regarding the other two - it may be a while before they are actually used as they are for a new kitchen in the future.

This is not the plumbers fault, its just how the renovation of the property has gone.

I have a couple more questionsin light of this.

If I periodically enable flow in both the 3m pipes, will this resolve that problem?

Also I don't understand why dead legs are causing the boiler to do what it is doing. It would be very helpful indeed if you could exaplain the general principle here.

Regards
FarmerJohn

 

[FarmerJohn]

Hi,
I get the reason now why the dead legs are causing the boiler to start when the cold is switched on and off.

Any ideas about the front panel not fitting properly?

Regards
FarmerJohn

 

[Deleted member 267285]

I’m not an oily, so a photo might be best

 

[FarmerJohn]

Have sorted out the door and dead legs and now all is well.

I was planning on putting a pressure gauge off of the incoming water supply, there would be a length of 15mm pipe to it about 100-200mm long.

Would this be considered a dead leg?

Regards
FarmerJo

 

[polesapart]

Nah, she'll be right.

You can use a compression fitting where you connect the guage, and slacken slightly to bleed any air trapped in the short pipe section.