Mains Pressure Hot Water System - Not enough hot water!

[TonyWarrington]

We have a mains pressure hot water system (approx 10 years old) which is now not delivering enough hot water to either fill the bath or provide enough hot water for a couple of showers.

Initially the hot water is ok then after a short time runs cold - usually can manage 1 shower for a few minutes or a few inches hot water in the bath.

Have had no luck tracing the hot water cylinder on the web - information on the cylinder:
Range
Flowmax Product Ref FM4735
Capacity 180 Litres
Mains Pressure Hot Water System
IMI

Before I call someone in is anyone able to advise me on why this should happen and make any suggestions for any actions I could take to improve the situation?

 

[Agile]

Range is one of the largest manufacturers of cylinders!

I expect you may have two heating elements and the one at the bottom has failed or been accidentally switched off.

We used to charge about £96 to replace but then we went to several which were a pain to drain and repair so we now charge £152 which seems a more typical charge but there are still a few people changing them for about £60.

The elements on the megaflow tanks are almost £50 just to buy.

Tony

 

[TonyWarrington]

Thanks for the reply have found similar looking units on the Range website. I believe that my model is a Flowmax indirect (no storage tanks in loft)

You suggested that we may have two heating elements and that the bottom one has either failed or been accidentally switched off.

Sorry if I have misunderstood the terminology but "Elements" and "switched off" suggest that you are referring to electric immersion type heating. There are no such fittings on this unit - if the boiler fails there is no backup for heating the water.

 

[Dan Robinson]

What boiler is feeding it them?

 

[Agile]

If its not electrically heated the it will be a failure of the heating control system.

If you follow the heating pipes back is there a motorised valve on one of them and if its only a two pipe type can you lock the lever in the slot?

Tony

 

[TonyWarrington]

The boiler is Baxi Solo 2 60 PF

I will have a look for a motorised valve.

 

[TonyWarrington]

Thought pictures may make more sense than me trying to describe
View media item 6186
View media item 6187
View media item 6188Found a "little" problem with this box - it is/was loose and hanging out of the cylinder slightly. I assume that this likely to be a temperature probe?

 

[Dan Robinson]

Your problem could also be with the blending valve in your first picture....

But I would eliminate the thermostat first...

 

[gas4you]

Don't know much about these, but is the flow max a thermal store?

If so I would check the primary pump has not stuck/seized.

Get that cyl stat fixed properly with a band around the cylinder.

 

[TonyWarrington]

Thanks to all for advice and suggestions.

After making sure that thermostat was properly in place I ran a bath checking on the water temperature (by hand) regularly.

After a short while the water temperature dropped from "fairly hot" to "luke warm" and only filling the bath (standard 5'6""?) by about 2 inches before the temperature drop. Continued to fill the bath to "normal" level to rule out any temperature layering - ended up with a very cool bath

So I think I need to pass this one on to a professional i.e. get a pro in to have a look

Thanks again

 

[Agile]

The thermostat hanging out would cause over hot water!

There are two pumps. You could check that the one attached to the cylinder is free to turn and when appropriate actually turning.

As Dave suggests, its quite possible its a thermal store but I have not been able to take a view on that from the pictures. I think perhaps not but it might be.

Tony

 

[Axel]

Feel the pipes on the cylinder. The top one should be hot from the hot water inside. If the water stored in the cylinder is cold, the cylinder stat should (on a 2 port) cause the motorised valve to open and a few seconds later fire the boiler. (On a 3 port it should fire the boiler straight away). The flow and return pipes coming out of the cylinder (the ones that go to the boiler) should be hot if the valves and stat and boiler are working ok.

 

[tigertail100]

Hi
Having exactly the same problem , local Plummer has no idea
did you find out what the problem was

Kind regards

 

[Agile]

Hi
Having exactly the same problem , local Plummer has no idea
did you find out what the problem was

Kind regards

I think that you need to find a competent plumber!

Its hardly rocket science and not all even have a degree!