Slow running Hot water (Carver)

[Mr_GWP]

Good Evening,
Apologies if this topic has been touched on before. We have a Bailey Senator California which has been well maintained over its life. It has the Carver water heater fitted which can run off Gas and Electric and which both work perfectly..however on our recent trip the flow rate has slowed which is causing some concern. Pump is working fine..internal tank pump (Cold water) and external tank pump (Cold water). Am I right in thinking that there is a non return valve fitted somewhere to keep the hot water from flowing back to the cold water tank ?
Many thanks

 

[otherclive]

Could be a NRV but also try removing the Tap end and clearing them. Sometimes they get scaled up with fine muck.

 

[Damian]

First thing to do is remove the ends of the taps and clean out the limescale that you will undoubtedly find.
The NRV is on the cold water inlet and unless damaged by frost will not be the problem.

 

[Mr_GWP]

Hi,
Thanks for the reply..I have cleaned the tap ends..white vinegar works well. The cold water comes through really strong..the hot feed is well lets say..slow..I've heard that it has a nrv on the feed..so will start there I think.
Thanks
Glenn.

 

[Damian]

There is no NRV on the hot water outlet.
The hot water will not be as strong as the cold in any case, but the other possibility is a build up of calcium within the hot tank, which will require specialist knowledge to remove with any success.

A later thought is that the NRV on the cold inlet has been damaged or is not seated correctly and that will need the inlet being replaced, but be warned, if attempting to remove the inlet valve it will almost certainly break and leave the stub still in the heater.
Removal is not simply a case of using an easy out !!!!!!, in fact never get an easy out anywhere near the heater !!!

 

[ProfJohnL]

As you have confirmed the cold water flow is good, we can discount the pump and the cold water piping to the taps.

One way to check the flow through the water heaters cold water inlet NRV, is to
[ol]
[*]Make sure all water taps are turned fully off
[*]Turn off the water heater, and water pump.
[*]Remove the external drain plug and allow any residual water to stop draining
[*]When the drain port has only drips or has stopped completely,
[*]Have someone turn the pump on.
[*]If the NRV is OK, cold water should flow readily with some force through the drain port. This means there is a problem with either the hot pipework or a blockage in the heater its self.
[*]If it only dribbles it suggests the heaters NRV is faulty or there is a blockage in the cold water feed pipe to the heater.
[/ol]

 

[Gafferbill]

+1
......I was going to add exactly what the Prof has written.

 

[Mr_GWP]

Ok great..thanks for the replies..will have a look when I get chance next weekend.
Thanks
Glenn B)

 

[ProfJohnL]

Thank you for your reply. Please keep us informed of what you find, as having the whole story may help another caravanner