Need advice (or have i broken something) - Hot water overflow pipe continous running

[Belcraig]

I consider myself OK at DIY, and have lots experiance with father inlaw (who was builder) in my my last house which was bought cheep and done up,

I bought a bigger new house two years ago with the intention of doing it up as a proper family home again with the father-in-law. Unfortualty last year he passed away. so i've been slowly getting on with the jobs that we planned back when i bought the house.

Anyway the problem.
In my last house I (with little supervision) fitted a pump for the shower, and wanted to do the same for this house so i isolated the water supplies cut the water pipes placed the pump in the way, (crudly explained but to the point). It all works great - fine job i said to myself, it all went smoothly. however later in the evening i heard the over flow pipe running, so i went back into the loft and the cold water storage tank was a good 2-3 inch above the normal level. (as indicated by the limescale mark )

I thought that this was a faulty ball (which i'd propped up) due to limescale build up so i lodged the ball up and as i didn't have the time then (due to lateness) i'd see to it the next day after work, I came home to find that the water level had not changed (wife had been in and was doing all normal activities so i assumed the water level in the tank level would have fallen.
As this wasn't the case i turned off the stoptap and the hot water valve. unfortualy due to getting in late i left it at that. the next day i went to work and when i got home the wife had turned on the stoptap to use the washing machines etc...and what she thought the hot water valve. However she hadn't actually turned on the hot water valve. the level in the tank was now just below the normal level that it is supposed to be.
However as i didn't originally know which way to turned the valve i turned it all the way one way and went to google which way was open and closed (as its not labelled) (righty - tighty, lefty loosely) (and the stem on the valve dosn't move up and down.)
after i went back to 'open the valve' - The overflow pipe (vent) from the hot water cylinder was flowing into the cold water cistern consistantly(the ball was still propped up and no water was coming out from this.)

So after all that rambling:

1 . Did me fitting the pump miss something out that my father-in-law would have done prevouly and i didn't notice?
2. And if so what have i broken/how do i fix
3. Has sods law just bitten me for doing something smoothly and decieded to brake something completly different and independent.

thanks for your help in advance.

Craig

 

[jtsplumbing]

Re: Need advice (or have i broken something) - Hot water overflow pipe continous runn

Hi mate just looking at photos , you need to put hot pump connection on surry flange or tapping on side of cylinder or you will be sucking in air down vent pipe ! the other thing is the cold water storage tank base made of chip board ?

 

[Paulus]

Re: Need advice (or have i broken something) - Hot water overflow pipe continous runn

Just thought - Is the cold feed to the shower pump mains or tank fed? If it's mains fed (or indeed tank fed if the CW and F&E tanks have a decent height difference) in this type of single ended monoblock pump it could be that the seal between the pump chambers has failed and the cold is pressurising the hot through the pump body (even when the pump isn't running). Relatively easy to check this.

Nice one mattweth, I've been following this thread and racking my brains but not got close to that answer to the problem.

 

[MattWeth]

Re: Need advice (or have i broken something) - Hot water overflow pipe continous runn

Nice one mattweth, I've been following this thread and racking my brains but not got close to that answer to the problem.

Cheers Paulus - When I worked in fridge we used to sometimes get this type of failure with twin impeller cooling pumps - seeing the picture of the pump made me think...

 

[stevetheplumber]

Re: Need advice (or have i broken something) - Hot water overflow pipe continous runn

had same problem with a similar pump where cold water was from tank in flat but hot was fed from tank on roof obviously we didnt find this out for ages

 

[pipeline]

Re: Need advice (or have i broken something) - Hot water overflow pipe continous runn

just out of interest,, could some1 explain to me, what your talkin about.. pahaha. interesting tread but dont understand, so could some1 tell me if my understanding is correct. the mains cold, broke pump and the pressure from the cold pushed the hot water back up the pipe to the vent and the cylinder???????? thanks men..

 

[PlumbBobBob]

Re: Need advice (or have i broken something) - Hot water overflow pipe continous runn

yes that's it basically

 

[Timbob]

Re: Need advice (or have i broken something) - Hot water overflow pipe continous runn

I have seen exactly this problem before with that same type of pump.

@pipeline, Basically, OP connected the mains cold water feed to the bathroom to the pump by as he mistook it for a tank fed feed. The type of pump he used has a seal between the hot and cold water all at the one end of the pump, see picture. this seal ruptured either previously to him fitting it, or possibly the mains pressure broke the seal as would have been designed to have balanced pressure between the hot and cold water supplies.

Without this seal in place the cold water was oushing through the pump into the hot pipework, forcing its way back up the hot pipework and discharging int the Cold water storage cistern in the loft via the vent pipe. Therefore causing the cistern to overflow.


A tell tale on this is the picture of the Cistern in the loft. You can just about make out that there are two outlets that have been capped off from the cistern, which to me would suggest straight away that there is a strong possibility someone has previously altertered the original tank fed coold and connedted it to the mais water to increase cold water pressure.