Shower Pump Fires up Intermittently

[rdo1104]

Hi

I have had a Salamander RHP50 fitted and last night it fired up intermittently when using a hot tap which is not connected to it. Here is the full layout and problem:

CWT & HWT are in loft, CWT is on a raised platform of around 5 foot and HWT is at loft floor level.

Pump is situated at loft floor level next to HWT and is piped via a Salamander S Flange as recommended.

The pump feeds 2 x showers both on 1st floor of house so have positive head, the bath and the sink in the bathroom.

All cold water feeds other than those from the pump are mains fed and all remaining hot water is fed through gravity via a separate pipe.

Prior to fitting the Flange 2 weeks ago the pump would intermittently fire up when one of the hot taps 'elsewhere' in the house i.e. not pump fed were used. I would then have to turn on one of th epump fed hot feeds to stop the pump!.

When the Flange was fitted, the problem stopped however I then had to fix a leaky tap and had to isolate the hot and cold supplies in the loft - this was on Saturday and then lo and behold last night the pump fired up intermittently.

There was a bit of knocking in the pipes before the pump fired.

So, I'm guessing that there is some air in the none pump fed side of the system that's drawing water back through the pump.

Question is - can anyone advise me how to remove the air - what steps do I need to take to isolate the supply and then re-commission everything.

Thanks in advance

 

[balcock]

I occasionally had a problem like this. It would only happen when the hot tap in the kitchen was switched off quickly. I figured that the problem was (in layman terms) the water bouncing or sloshing back the other way in the pipe (same as it bounces side to side in your coffee cup) to the hot water cylinder and forcing its way out of the hot feed for the pump. This looks like a flow of water to the switch in the pump causing it to turn on. In my case it would only be a half second burst and the pump would turn off again.

 

[conny]

Can't help with this but someone in plumbing could.
Suggest you get the mods to move it for you.

 

[OvertonPlumber]

fit a single check valve to the hot outlet of the shower pump. this will stop other supplies causing a bowwave in the hot water tank and lifting the flow switch in the shower pump/

 

[FabianTmobile]

My shower has packed up at the moment, disaster, I can't function without a decent shower in the morning.

Pump has gone so there's no pressure, was working fine one evening and then the following morning the water was barely dripping out.

Is this likely to be a limescale build up or something like that?