Hot water fluctuations in shower, help!

[irusmal]

Hi,

My first post here, I hope someone will be able to help me out or point in the right direction.

I have moved into new place, which have very old combi boiler, I think it is from Chaffoteaux, but i don't know the exact model. Plumber who was in the property few months ago said it is at least 15 years old and they dont produce these anymore, it is magic that it survived this long.

Boiler works ok for central heating, but when using it in the shower water does not mix properly, it is either very hot if you have hot water tap open or very cold if you reduce the hot water flow. I noticed that boiler fires on when hot water flow is at full, when you reduce it to half, it switches off and after 2-3 min water gets cold and you have to turn hot water tap fully open to get hot water again (after another minute or so). When hot water is fully on, it completely overtakes cold water and you get very hot shower, which is impossible to use. If you reduce hot water flow to half, as I mentioned earlier boiler switches off and you get cold water after about 2 minutes. This makes impossible to take shower, you are either getting very hot or very cold water out.

I was planning to change the boiler anyway, but thought I would ask here whether the problem is definately with boiler or maybe with shower head or something else? Water pressure seems to be good.

I hope i could explain the problem, thanks for your responses!

 

[irusmal]

anyone to advice on this?

 

[kevplumb]

if its a thermo shower on a "celtic "

it sounds about right

 

[Goldberg]

Do you have a hot water temperature control on your boiler? If so, what position is that on?

Also, what's the make and model of your shower?

 

[kevplumb]

oh god the plumbing guru is online

whats your job again

apart from part time plank

 

[Agile]

The boiler has a fault as it should turn on at about 2.5 litres per minute hot water flow rate.

It is however quite an old boiler and would really be beter replaced unless the property is due for demolition shortly!

Tony

 

[irusmal]

Hi guys,

Thanks for your responses.

Hot water temperature control is pointing in the middle of min and max scale, but it is impossible to turn it. It is either stuck or not working. Boiler is very old and was probably never serviced.

There is no make or model mentioned on the shower mixer, but is just a simple shower which looks something like this:
http://www.argos.co.uk/static/Produ...|cat_14418043|Shower+accessories|14418054.htm

but without the arch and soap dish, just a wall socket to slot the shower head in.

 

[kevplumb]

is this the boiler

 

[irusmal]

Thanks Agile, I am expecting a plumber to come and have a look tomorrow, will let you know what he says. But from what you guys are saying it all points to the old boiler.

It is however quite an old boiler and would really be beter replaced unless the property is due for demolition shortly!

Tony

omg, i hope they don't demolish it, because i moved in only recently!

 

[irusmal]

is this the boiler

Kevplumb, yes this is the boiler exactly!!! I was searching the web for the picture but could not find anywhere...

 

[kevplumb]

be kind to it

take it somwhere quiet and shoot it

they where never very good when they where new

 

[Goldberg]

Hot water temperature control is pointing in the middle of min and max scale, but it is impossible to turn it. It is either stuck or not working.

Oh dear. I think you know where this is heading, especially considering that C&M boilers are horrible to work on.

There is no make or model mentioned on the shower mixer, but is just a simple shower which looks something like this:
http://www.argos.co.uk/static/Produ...18043|Shower+accessories|14418054.htm[/QUOTE]
Er, yes, but it would be more useful to know what the valve is on the other end of that hose.

 

[Agile]

I think the temperature control is actually a water flow rate control valve and they often jam after so long.

Better left untouched as you can control flow at the tap.

I have repaired that fault on those but not for some while.

If I remember correctly you have to be careful not to get wet!

Tony

 

[kevplumb]

Oh dear. I think you know where this is heading, especially considering that C&M boilers are horrible to work on.

is that from experience then

most of the time if the flow control is seized it will leak if disturbed

the diaphram in the change over valve will prob be streched / pinholed as well

 

[irusmal]

Er, yes, but it would be more useful to know what the valve is on the other end of that hose.

Hi Goldberg, I cannot see what is underneath the bath unfortunately, it is all closed with bath panel and there is no easy way to get there without removing/breaking the panel