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

 

[marleyco]

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

I can't see how you fitting the pump could have done this unless you have pipe's wrong way which would then pump back up the hot and up the vent. You may think the shower pump is doing its job as the cold is being pumped in the right direction. Also if for some reason the valve You turned off was after the hot tank this too could expand up the vent, if the valve has jammed shut.

 

[PlumbBobBob]

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

hi craig welcome to the forums. which pipes did you utilise to pipe up the pump?

 

[Belcraig]

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

hi craig welcome to the forums. which pipes did you utilise to pipe up the pump?

The pump pumps both the hot and cold water supplies to the bathroom.

 

[smileyplumber]

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

could it be that you have conected the pump to the cold mains and its pushing back through the shower valve ?
just check that both hot and cold are tank fed

 

[Best]

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

Send a photo or two of pump & pipes. This will be interesting.

 

[Best]

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

could it be that you have conected the pump to the cold mains and its pushing back through the shower valve ?
just check that both hot and cold are tank fed

That will do it! :grin:

 

[PlumbBobBob]

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

could it be that you have conected the pump to the cold mains and its pushing back through the shower valve ?
just check that both hot and cold are tank fed

thats what i was trying to get at

 

[Belcraig]

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

could it be that you have conected the pump to the cold mains and its pushing back through the shower valve ?
just check that both hot and cold are tank fed

Isolating the pump off from the rest of the house dos not solve the issue.

 

[Belcraig]

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

Send a photo or two of pump & pipes. This will be interesting.

There are two pipes leading to the bathroom - one hot, one cold.

the pump is placed correctly - as the water flows in the directions of the arrows on the pump. also turning on the shower water flows at pressure with both the hot a cold taps. - surely if the pump was incorrect then water wouldn't flow at pressure outof the shower.

 

[Belcraig]

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

could it be that you have conected the pump to the cold mains and its pushing back through the shower valve ?
just check that both hot and cold are tank fed

The water is running constantly not just when the pump is on.
If i isolate the pump. (which is all the supply to the bathroom) then the problem should stop?? This is not the case.

 

[marleyco]

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

Is it possible, the tank is naturaly expanding due to hot water being to hot, try turning hot water off, see if it does it when its cold

 

[Best]

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

The water is running constantly not just when the pump is on.
If i isolate the pump. (which is all the supply to the bathroom) then the problem should stop?? This is not the case.

If the water is running when pump is off, you can only either have a fault where the mains can go into hot vented supply, - like a faulty tap, OR you could have a fault in the coil inside hot tank, if the expansion heating tank is very high above. Seems you have mains problem, unless I am missing something.

 

[PlumbBobBob]

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

can you post some pictures of pump and connections and all other pipework in airing cupboard. presumably that is where you have sited pump?

 

[Belcraig]

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


Ignore thefact that its in a wash basin, I've just not taken it out of that yet, Its in there so the insulation didnt get wet.
The pictue is slightly mis leading the 'silver flexibles' are not twisted or kinked in. the supply comes from the left and the bathroom is on the right. the Small white mark on the right of the pump outlets is an arrow poining upwards (not sure if you came make that out properly)

Top of hot water tank. the line going directly up is running the the cold water cistern,
when the tap in this picture was off the level in the cold water tank dropped, turning this tap on again caused the level to rise to its currently high level.

 

[Belcraig]

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

The top of the hot water tank isabout level with the bottom of the cold water cistern

 

[Best]

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

When the mains water is turned off at stopcock where it enters house, does the vent pipe stop flowing? This would rule that in or out.

 

[Belcraig]

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

The exit of the vent pipe is cueently at the level of the water line and so cannot see if its over lowing will investigate tomorrow and see.

 

[Best]

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

Usually if the mains can enter the hot supply, it will rise through the expansion only if given good flow. Normally on a small fault on, say, a tap, it goes up the hot tank cold feed pipe from bottom of hot tank to bottom of cold tank.
If on larger flow, mains will go up the expansion.

Only other time I have ever seen cold tanks overflowing not due to ballvalve, is when the coil of the heating in cylinder is leaking & allowing the highest tank - often the exp tank in vented heating systems, to raise level in lower tank & cause overflow.

 

[Belcraig]

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

ok so i closed the tap linking the cold water cistern to the ho****er taplast night. thinking that this would allow the water to level to fall, after several showers and the normal morning routine, (Ball is still propped up therefore is not replenishing the cold water cistern)

The water level has not changed, therefore the hot water must be drawing off of the mains as well?

Yesterday however when the valves were in these positions, stopck on and the valve seperating the cold and hot tank was off, there was no water comunication.

however it seams to be pointing to a seperate fault?

 

[MattWeth]

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

As others have said, my guess is that the coil in the hot water cylinder is leaking and the high tank is pressurising the cylinder and forcing water out into the storage tank. The operation of the pump could have provided enough shock / hammer in the pipework to fracture a dodgy joint in the cylinder (it looks quite an old cylinder?)...

I'd try to isolate the flow and return to the cylinder and pressure test the coil.

Edit: 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.

 

[PlumbBobBob]

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

that would be the reason why the hot into the pump is hot but the outlet is cold

 

[Belcraig]

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

Thanks to everyone for all their advice,
I moved all the stuff aroud in the loft last night to check the piping and not refer to the drawing we made a year ago, and the cold water is mains. Thanks to MattWeth,when i isolate the pump i didn't think about the pump being Broken. i think the problem was the seal in the pump. I removed the pump and replaced with some new piping and the water is back to normal.

 

[MattWeth]

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

Great - glad you've found the source of the problem (and that my idea appears to be correct)

One thing is, that according to the regulations, you shouldn't have a pump connected direct to mains cold water - you should really be pumping from a tank. This may have contributed to your pump failure as they aren't designed to handle mains cold water pressures on the inlet.

cheers
Matt

 

[Belcraig]

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

plansthat i have have it attached to the gravity feed. But as father-in-law was leading it may be that this was his plan and they wern't just written down as i have a fair amount of copper piping to place, but havn't found where this goes on the plans, and just assumed it was left over from some of the changes we made.