booster pump

[yebaws]

I want to install a pump to boost hot water flow. Have looked at shower pumps and they seem to involve a lot a flanges, gravity loops etc....

Is there a way that I could fit a pump to the cold water feed at the bottom of my HW cylinder and thereby boost the pressure of all the hot water coming out. Seems to me that this would have the equivalent effect of raising the header tank, but I'm guessing it's not that simple....

 

[yebaws]

I've thought about this and worked out the answer myself - If I did that I'd end up pumping a load of hot water up the vent pipe....

So, I'll have to fit a pump to the outlet...

There's one cylinder exclusively for one bathroom (with shower and sink). So to avoid putting in a flange, I want to fit the pump before the tee that splits to the shower and the sink (thus boosting the pressure of both the sink and the shower). Assume there would be no real problem with this other than a drop in pressure to the shower if the sink tap is opened (but probably less of a drop than before the pump was installed)?

My other thought is that, if I'm not using a flange and the pump will be in the same pipework as the vent, the pump may draw down air through the vent. Or would the flow up from the cylinder prevent this? I guess I'd have about 1.5 M between the tee for the pump and the top of the hot water storage tank and I want to fit a 1.5 bar pump. If air down the vent was a problem, is there any reason why I couldn't fit a check valve in the vent pipe to stop it coming down?

 

[seco services]

whats wrong with fitting a flange if your going to do the job right ?
and no you can't fit a nrv in the vent pipe.

 

[yebaws]

My tank outlet is 1/2 inch - which is the root of the problem. I don't know if you even get a surrey flange that small and if you did the flow rate would be tiny. I have an Essex flange and it says max temp 60 deg C for rubber washers. Even if I set my thermostat at 59 deg, whos to say it is accurate and the washers won't perish in a few years?

Basically I don't want to risk messing up my tank if I can avoid it.

Why would fitting a nrv in the vent be a problem?

Thanks...

 

[seco services]

cause the vent pipe is a saftey pipe and shouldn't have any restrictions or valve along the pipe.

 

[doitall]

I think the correct answer is follow the manufacturers instruction or don't install it.

As DrDrivel, aka WaterSystems, etc etc,etc,etc, would say an exploding cylinder can and will make a big bang and a lot of mess, assuming you're still around to clean it up.