No flow from my hot taps!

[rmab]

Hi all!

 

For the last 8 weeks ive had no flow from the hot taps! The cold works as does

the pump. I drained the hot tank down but due to the design of the system

there is a part of the red pipe where water will sit and freeze!!

 

The length of this could easily be 2 metres.

 

It was minus 17 here but could it STILL be frozen as it only dribbled through

for a few seconds this afternoon ??

 

Thanks

 

Rich :-(

[Guest Tracker]

Are you asking a question - if so what question - or are you simply telling us that you have a problem to which you already know the answer?

[rmab]

Well I guess the question is do you think

that it could be possible that it is still

frozen??

 

Or does anyone have any other thoughts/ experiences??

 

Thanks

 

R

[Guest Tracker]

It depends where you live, how the van is parked, and the temperature now?

 

Have you tried warming it along its length with a hair dryer?

 

Have you had the heating - or some form of heating - on in the van to raise the temperature with the lockers and cupboards all open to circulate the warmth?

 

Have you tried disconnecting it at various points to try and determine where the problem is?

 

Assuming there are no leaks along the whole length of hot water pipe have you considered the possibility of an air lock?

 

If you are in no great rush to use it you might consider just leaving it until a warmer period whenyou can be absolutely certain that it is not frozen?

[spospe]

If the vehicle has a Carver water heater, the problem could be that the ice in the pipe feeding cold water to the hot tank has pushed the non-return valve into its sealing washer and jammed it shut = no flow.

 

This has happened to me due to water remaining in the pipe, freezing and forcing the valve shut (even after the ice melted).

 

Easy job to repair, either jar the valve free if the damage is not too great, or replace valve (get them from O'Leary at: http://www.olearymotorhomes.co.uk/).

 

If your heater is not a Carver, then it could still be as I have described.

[rmab]

Thanks, this could be the reason.

 

Is the non return valve inside the heater or just

somewhere along the cold water feed pipe?

 

The unit is a Henry (very similar to the Carver).

 

Rich

 

Although crucially the water IS getting into the water

heater.

[Brambles]

Hi, the none return valve is one fitted is likely to be part of the top connection to the tank. Bit confused on the carver types, but equally could be a strainer in there as well which may be blocked if icing up has caused scale inside tank to loosen it.

 

Edit - afterthought - Have a feeling the valve in the top connection might be a pressure relief valve and goes to a drain pipe -- maybe it is leaking. Have you checked for a pull of water under vehicle after running the hot?

[rmab]

Hi

 

I have put the gas heater on plus a fan heater.

 

The Carver unit was replaced last year (Aug) with

the new Henry one and has been used 6 times

without problems.

 

There doesn't seem to be any non return valves

or strainers. There is one where the pump sucks

the water from the tank. I have filled that with

warm water.

 

The water heater has a polystyrene jacket, should I try

to remove that and see if I can see anything??

 

The pipes are these pushfit ones, how can you pull them

apart to see what's flowing?

 

On my wifi in the van, so all ideas can be

acted on immediately!!

 

Rich

[rmab]

I have disconnected the hot outlet pipe and find that the water is not coming

out of it. I know the water is getting into it as when I undo the drain valve water comes out.

 

Instead of the fitter using a non return valve at the hot outlet

they just used a connector and it's clear.

 

I am wondering then if there is some valve or pressure reset

on the heater itself?

 

I don't have a manual, any ideas anyone??

 

Rich

[rmab]

Well I've found the pressure relief valve on the

outside if the unit.

 

The heater is full of water, is heating the water but

nothing is coming out of the hot outlet on the heater!

 

Mystified!! Ideas anyone?

 

Rich

[Brambles]

There are various kind of connectors and push fits but..probably the connection to the tank is a compression gland where the barrel of the connection is dimpled and if so most likley just loosen by turning and unscrewing a bit and pull it off. The other end is push fit and there should be a collar sticking out very slightly around the pipe, Push the collar down into the connector, push the pipe in a bit as well after the collar is pressed in, and then pull the pipe keeping the collar pressed and the pipe should come out.

Some connectors unfortuately require a tool to be inserted around the pipe but I do not think those types will have been used.

 

It is entirely possible scale/muck/crud/gunge has just built up in the feed pipe to taps and needs blowing through, if you have a trickle it may clear itself once hot water starts to get through. If you an get the pipe off the heater tank then you could blow backards through the tap set to hot.

 

Keep a few old towels stuffed around anything diconnected to catch any water just in case something starts to flow.

 

[spospe]

On the Carver heater the non-return valve is fitted in the pipe feeding the heater and from memory it was in the lower of the two water pipes. It is very easy for a small quantity of water to get trapped in the pipe, freeze and cause the problem you have described.

[rmab]

Thanks for all the advice so far.

 

With the pump working it is pumping water into the heater and

the heater fills with cold water. So no blockages there.

 

I have then removed the hot water exit (red) pipe from the heater.

 

With the pump on you would expect hot water to come out of the exit hole

in the heater, but it doesn't !

 

Hmmm, I think I am going to take this down to a workshop

tomorrow. It's as if there is some blockage in the tank but it's nearly

new!

 

Thanks for all your advice

 

rich

[crag]

Sorry to hijack this thread but can I throw another spanner in the works as I've got this problem this weekend.

 

In playing around I found that leaving the hot tap open in the kitchen area and switching both hot and cold taps on in the bathroom, water will come out of the hot tap in the kitchen area.

Switching the hot tap off in the bathroom but still leaving the cold tap open, will also stop water coming out of the hot water tap in the kitchen.

With all taps off, or just opening a hot water tap the pump is gunning on/off on/off all the time. Had a bit of a play with the pressure switch but that didn't help.

 

I've had the heating on most of the weekend and it wasn't freezing temperatures where the van was, so I don't expect anything to be frozen, but am suspecting some air blockage somewhere.

 

Looks like I have a maintenence weekend coming up but not sure where to start.

[Brambles]

Rich,

Having now looked at detailed diagrams and from what you have said it looks like very much there is a blockage in the exit passage ways from the tank. The exit pipe unscrews and being a narrow bore maybe dirt is caught behind it. At the other side of the exit pipe fitting, under the extrenal cover is a pressure relief valve. This would not cause a block but now may itself be blocked and should be checked it is clean/clear for safety.

Jon.

[Brambles]

crag - 2010-01-24 8:11 PM

 

Sorry to hijack this thread but can I throw another spanner in the works as I've got this problem this weekend.

 

In playing around I found that leaving the hot tap open in the kitchen area and switching both hot and cold taps on in the bathroom, water will come out of the hot tap in the kitchen area.

Switching the hot tap off in the bathroom but still leaving the cold tap open, will also stop water coming out of the hot water tap in the kitchen.

With all taps off, or just opening a hot water tap the pump is gunning on/off on/off all the time. Had a bit of a play with the pressure switch but that didn't help.

 

I've had the heating on most of the weekend and it wasn't freezing temperatures where the van was, so I don't expect anything to be frozen, but am suspecting some air blockage somewhere.

 

Looks like I have a maintenence weekend coming up but not sure where to start.

 

Confused a bit here.

 

Does Hot water come out of your bathroon tap, and are your bathroon taps mixer type taps.

What I am picturing in my mindis a blockage in the hot water feed to both taps further back in teh system (could even be at heater as well) and when you open the bathroom tap with both hot and cold selected the cold pressure feeds both the outlet and back down the hot pipe to feed the kicthen tap. If seperate taps this would not make sense or happen and is very wierd.

 

 

[crag]

Hi Brambles

Both kitchen and bathroom taps are mixer type. Hence going back and forth between kitchen and bathroom.

I'm kind of thinking the blockage is at the heater. It's all been drained out and taps open since it's last use at New Year.

 

I must have been getting some water into the heater as some came out of the drainage hole when I drained it down again today. But I don't believe it was even half full.

 

When I fill the tank I wait till it's nearly half full, then switch the pump on which fills the hot tank. That didn't happen this weekend. As I mentioned in my earlier post, with taps shut, or only the hot taps open the pump is gunning on/off.

There does not seem to be any pressure at all from the hot taps yet emptying what was in the hot tank today, water did gush out the drain hole as if there was some pressure there.

 

Thanks

[Brambles]

Certainly sounds like the outletis blocked. Have you tried leaving the hot taps open for a while with the pump gunning on and off to see if it eventually builds up enough pressure to clear. Stil, as you say does sound like outlet is blocked -- same again here I fear, check the outlet pipe from heater.

 

Maybe someone will come along with a magic tip for all. Ahh yes, press button A and all will work type thing...but doubt it.

Jon.

[rmab]

Thanks Jon

 

Yes I have unscrewed both the small bore exit pipe and dismantled

and cleaned the pressure release valve. They were both clear though.

 

I wonder what makes the hot water come out of the cylinder?

 

Is it the pressure from the pump, and the unit seems to be sealed from this point onwards. It was building pressure up in the tank, as I could manually release the pressure, but obviously it wouldn't push hot water out.

 

Now I am wondering if it needs to be replaced?

 

Rich

[crag]

I did leave the pump going for a while. What I was hoping to achieve by getting a hot water tap running (be it by opening another hot tap and a cold tap) was to clear any air blockage.

 

I can't quite get my head round

a) why the pump is gunning when I can't get any water through the hot pipes

b)why I can get water through the hot pipes by opening other taps.

 

Will study my carver manual this week and go and have another play at the weekend.

 

 

[Brambles]

crag - I think it is gunning as it is slowly managing to push some water into the hot sytem, so a small amount of air (edit - or water) must be coming out the taps.

[Brambles]

rmab - 2010-01-24 9:29 PM

 

Thanks Jon

 

Yes I have unscrewed both the small bore exit pipe and dismantled

and cleaned the pressure release valve. They were both clear though.

 

I wonder what makes the hot water come out of the cylinder?

 

Is it the pressure from the pump, and the unit seems to be sealed from this point onwards. It was building pressure up in the tank, as I could manually release the pressure, but obviously it wouldn't push hot water out.

 

Now I am wondering if it needs to be replaced?

 

Rich

Yes, pressure from the pump will leave a bit of pressure in the tank, and a small amount of water will come out the drain, also the weight of the water cause slight 'suction' in the tank. Does the tank drain OK?

Wondering if the pressure relief valve also acts as a one way bleed valve to allow tank to drain without opening a tap.

It has to be a blockage somewhere inside the heater tank and outlet passages.

The units are fairly easily dismantled, but like a lot of these things usually best to fit new seals. As it is fairly new you will probably get away reusing old seals. I cannot see it being covered by warranty if it is abockage unless something which is part of the unit has shifted and caused the block. So see no harm in dismantling as long as you know what you are doing. I would perservere though with trying to get water to flow through even by draining and then trying to pump air or water back into the unit through the outlet.

What you could try doing is squeezing some lemon juice into the outlet so it will disolve any scale in that area for a few hours and then see if water flows.

Also check you can pump water though the pipes to the taps, maybe a temp pipe running from the inlet feed pipe, to the outlet feed pipe so bypassing the heater. Easier said then done if you need to find a short length of tube to do so.

 

edit - spelling.

[rmab]

My issue was remedied by a new

non return valve at the cold water

inlet on the Henry.

 

Thanks to all those with advice

 

rich :->

[Ocsid]

Glad your now sorted, but to answer your earlier question.

 

The pump pushing cold water into the bottom of the Henry, via the non return valve, is the only thing that "pushes" hot water out of the top connection and on to the hot taps.

 

Clearly that non return valve was sticking closed.

 

What was throwing me is you saying the Henry was "filling", as that indicates the non return valve had been opening at some time.