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Hot water issues


vfrdave

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3 hours ago, Nickfromwales said:

Who fitted the TS? Did they use a pressure reducing valve at the cold water inlet, directly before it? Deffo a mixing fault due to missing / fouled NRV's.

You could solve this possibly by fitting a whole of house PRedV at the incoming cold mains and set that to 3.5-4 bar. Sounds like you have good cold mains pressure adding to the problem.

Getting the cartridges out may or may not allow you to solve the problem, if you cannot get NRV's in there / get to the ones that are U/S. Do you have the manufacturers literature for the basin and the shower units?

Plumber fitted the TS. There is one of these TRV Multi-blocks ( pressure reducing valve and cold mains PRV combination valve with a balanced outlet for matched pressure reduced cold out to the mixer taps ) which is set at 3 bar, though I think I might want to change it for an adjustable one at some point.

What do you mean by get to the ones that are U/S? Manufacturer literature is very poor for both it is more just diagram and measurements.

 

3 hours ago, Nickfromwales said:

The cold water supply to the bathroom ( any mixer outlet ) should be the same feed that goes into the TS cold side

This is the case cold feed comes off the mutibloc and then branches to each of the rooms (3 * bathroom & kitchen/utility).

 

All seems to hinge on a problem in the bathroom, a nrv would sort the other rooms out but how do I sort the bathroom out.

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20 minutes ago, vfrdave said:

Plumber fitted the TS. There is one of these TRV which is set at 3 bar, though I think I might want to change it for an adjustable one at some point.

What do you mean by get to the ones that are U/S? Manufacturer literature is very poor for both it is more just diagram and measurements.

 

This is the case cold feed comes off the mutibloc and then branches to each of the rooms (3 * bathroom & kitchen/utility).

 

All seems to hinge on a problem in the bathroom, a nrv would sort the other rooms out but how do I sort the bathroom out.

Do you have a TS or an UVC?

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Then you should NOT have that multi-block in there at all !!

That was supplied by your plumber then, because Trevor doesn't send multi-blocks out with a TS as its not a HWC but an instantaneous hot water heater with a coil volume of less than 15L. 

The coil in the TS is good for north of 7 bar ( nominal ), and rated at 10 bar ( max ). Get rid of that and watch what happens to your flow rate to the shower ;) 

Are you 100% sure the cold feeds to the same bathroom come from the balanced cold outlet of that control group ( multi-block ) ?

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18 minutes ago, Nickfromwales said:

Then you should NOT have that multi-block in there at all !!

That was supplied by your plumber then, because Trevor doesn't send multi-blocks out with a TS as its not a HWC but an instantaneous hot water heater with a coil volume of less than 15L. 

The coil in the TS is good for north of 7 bar ( nominal ), and rated at 10 bar ( max ). Get rid of that and watch what happens to your flow rate to the shower ;) 

Are you 100% sure the cold feeds to the same bathroom come from the balanced cold outlet of that control group ( multi-block ) ?

Interesting cause I didn't think it was needed but there is a reference on the side of the TS saying something about 3bar max which made him insist that it was needed.

 

Yes bathroom cold feeds definitely come off the multiblock.

 

IMG_20190712_101045.jpg

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1 minute ago, Nickfromwales said:

3 Bar max is the cylinder rating NOT the coil rating ;) You 100% do not need it, and it's strangling your flow rate which is why the shower is a bit crappy.

Lose the MB, link through and give it a test run. 

 

That does make sense. So can I just replace the multibloc with a t piece essentially and some more copper?

2 minutes ago, Nickfromwales said:

That's a LOT of 22mm pipework for that many radial runs too. Probably contributes to a lot of extra delay getting hot water out of the basins. ? Looks neat with him though :) 

Why 3 x filling loops?!?

Kitchen is the furthest away and it wasn't too bad when testing yesterday.

Fill loops for UFH, small rads circuit and then the boiler circuit.

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Just now, vfrdave said:

That does make sense. So can I just replace the multibloc with a t piece essentially and some more copper?

Yup. Make sure you put a cap end on the discharge pipe so you don't get ant back-flow / draughts through it. 

 

1 minute ago, vfrdave said:

Kitchen is the furthest away and it wasn't too bad when testing yesterday.

Fill loops for UFH, small rads circuit and then the boiler circuit.

OK. Just a bit OTT that's all.

The lot should just fill of the one boiler loop? It's all one unified body of water ;) 

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1 minute ago, vfrdave said:

Does the tank prv and tundish not need to connect to it?

Absolutely. That's the reason I am saying that you should cap the redundant one that will be left open ended after you remove the MB. Otherwise if the TS ones open and discharge the water will squirt out of that then open end.

Comprendez vous?

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9 minutes ago, Nickfromwales said:

Absolutely. That's the reason I am saying that you should cap the redundant one that will be left open ended after you remove the MB. Otherwise if the TS ones open and discharge the water will squirt out of that then open end.

Comprendez vous?

Honest answer it isn't actually there yet so no concern when the multibloc comes out ?.

 

So action list:-

- Multibloc out probably need plumber as I have never soldered. This will hardly sort my bathroom woes.

- should I put a nrv on each of those hot 22mm legs? 

- anything else?

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23 minutes ago, vfrdave said:

Honest answer it isn't actually there yet so no concern when the multibloc comes out ?.

 

So action list:-

- Multibloc out probably need plumber as I have never soldered. This will hardly sort my bathroom woes.

- should I put a nrv on each of those hot 22mm legs? 

- anything else?

-Use compression fittings ;) 

-No. Chop the MB out and try the bathrooms first.

-If it all goes wrong, we never spoke OK. 

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6 minutes ago, Nickfromwales said:

-Use compression fittings ;) 

-No. Chop the MB out and try the bathrooms first.

-If it all goes wrong, we never spoke OK. 

I have faith in your advice.

Multibloc out and I will report back then.

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Take the 28mm pipe out of the 1/4 turn lever valve and renew from there. Put a 28x22mm internal reducing set into the nut instead of the olive and thatll get you back onto 22mm pipe from the valve. Keep the top brass nut and fit your straight connector into there. Fit the tee to the horizontal pipe, should fit on the same nut, and just fill in the gaps with 22mm pipe.

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I expect you have already tried this or can't but...  I would turn on the cold supply and run cold out of the shower, tap and to the WC to get the pipes cold. Then turn off the cold supply and run the kitchen taps. Then feel the temperature of the cold pipes at the shower and the bathroom tap. If one of those is now warm the problem will be with that device. 

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2 minutes ago, Temp said:

I expect you have already tried this or can't but...  I would turn on the cold supply and run cold out of the shower, tap and to the WC to get the pipes cold. Then turn off the cold supply and run the kitchen taps. Then feel the temperature of the cold pipes at the shower and the bathroom tap. If one of those is now warm the problem will be with that device. 

Good point. That's what I did before to diagnose a duff NRV in a shower after we fitted a new combi and the customer was trying to blame us. That was the first time I came across this problem. A bugger to find on your own doing process of elimination ( cutting ad capping all over the place !!! ). Every day is a school day.

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9 minutes ago, Nickfromwales said:

Good point. That's what I did before to diagnose a duff NRV in a shower after we fitted a new combi and the customer was trying to blame us. That was the first time I came across this problem. A bugger to find on your own doing process of elimination ( cutting ad capping all over the place !!! ). Every day is a school day.

@Temp the only place I can check is beside the TS, after that all pipework is buried in the floor or walls.

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4 hours ago, vfrdave said:

@Temp the only place I can check is beside the TS, after that all pipework is buried in the floor or walls.

The body of the unit will get warm to the touch by comparison after first running stone cold water through it. Just being able to feel the bits you have exposed should suffice.

One will stay chilly the other won’t. 

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