Thermal store quick question

[amtrakuk]

As part of an accommodation "deal" I've just had a brand new 172 litre thermal store purchased and fitted by a mate in the cellar to replace my 12Kw on demand Redring Powerstream.

I have it running as a Direct (electric) thermal store using 2x 3Kw elements, both set to 70 degrees. I have 100mm of insulation on the tank. I let it heat up overnight and today on both elements.

Ran a bath this afternoon and as I swished my hand though the water was expecting HOT water instead had warm water. I ran downstairs and grabbed the room thermometer and my bath was 38 degrees - a luke warm bath!

Doing some investigation I made sure the blending valve was on the hottest it could go - removing the cap off it and twisting it to max. About 15 litres comes out nice as hot as expected but then soon cools down to a moderate 35-40 degrees, enough for a cool shower or bath.

Still to find out if its the blender valve or the thermal store is at fault. At this rate (taking into account standing heat loss rated at about 2Kw a day) I would get comparable performance (but not the flow) from my 12Kw Redring Power Stream. And for a single person, the thermal store would be more expensive to run.

Perhaps there is a fault somewhere or is the water running though too fast to be heated by the heat exchanger.

Annoying thing is I have paid out over £200 for parts and labour to get it installed on recommendation by a mate only to get 15 litres of hot water then luke warm water.

 

[Agile]

Firstly, you should not be adding to someone elses thread. You should be starting your own.

Its never a good idea to get a "mate" to do any work for you.

Usually the "mate" is not qualified, unable to notify appropriate bodies and doing the job for a cash payment which means there is no route for complaints when something goes wrong.

My first question would be what is your "mate's" qualifications and experience for installing and setting up your installation?

Tony

 

[amtrakuk]

My mate isnt qualified as a plumber but even then a thermal store is simple to install, (Mains water in, Hot water out, no need for TPR Valves, expansion vessels etc). The Navitron was pre plumbed with a blending valve. There doesn't appear to be a problem with the flow,it filled the bath within 7 minutes.

Just don't know why I would get a kitchen sink full of hot water (as expected) and it to then turn to luke warm water.

 

[numpty1]

Leak /faulty immersion heater or the blender not a lot of components to go wrong,is the store up to temp?

 

[Nordio]

You should have had an unvented cylinder or an ordinary gravity fed HW cylinder installed.
I don't know why people bother with thermal stores.

High flowrate to your bath probably resulting in lower temperatures and lower to the kitchen sink resulting in higher temperatures.
With instantaneously heated dhw it's all about flowrates due to the nature of heat exchangers.

 

[transam]

There is a big estate down the road that have all been installed with Gledhill thermal store's , nothing but aggravation , I think Gledhill do a fixed price repair £360 I think ?? so I was told !!

 

[ajstoneservices]

Your "navitron" store is in fact made by Newark http://www.newarkcoppercylinder.co.uk/ Give mark a ring he'll be able to advise you better. My guess is, he'll tell you to increase the store temperature to 85c, not easy when it's a direct.

 

[Agile]

My mate isnt qualified as a plumber but even then a thermal store is simple to install,

Well you may think that its easy to install but to do the job properly is obviously beyond the abilities of your mate!

As always the correct advice is to use a qualified and identifyable professional whom you can expect to be able to do the work or call in appropriate assistance if he cannot.

I presume you paid your mate say £50 to fit it for you.

Now you could ask for the £50 back so you can call a professional to diagnose the problem for you.

Tony

 

[amtrakuk]

Your "navitron" store is in fact made by Newark http://www.newarkcoppercylinder.co.uk/ Give mark a ring he'll be able to advise you better. My guess is, he'll tell you to increase the store temperature to 85c, not easy when it's a direct.

The thermostats on the immersion elements are at 70 degrees. Mate who installed it has asked Newark and they have asked him to do some tests. they suspect the Temperature Mixing Valve is at fault as it is closing down too much, they also said the mixing valves hottest setting should be 60 degrees.

They also say the cylinder should be fine using it in the configuration (direct heating), the heat exchanger is rated at 100Kw. Personally not sure how good or bad that is, I had a look on google and it seems a rather complicated equation to work out heat exchanger values!

Im assuming the cylinder is up to temp as both elements click off after about an hour (after a bath run).

Only time will tell, my mate should be here later this evening to carry out the tests they have asked him to do.

 

[amtrakuk]

My mate isnt qualified as a plumber but even then a thermal store is simple to install,

Well you may think that its easy to install but to do the job properly is obviously beyond the abilities of your mate!

As always the correct advice is to use a qualified and identifyable professional whom you can expect to be able to do the work or call in appropriate assistance if he cannot.

I presume you paid your mate say £50 to fit it for you.

Now you could ask for the £50 back so you can call a professional to diagnose the problem for you.

Tony

No hes done it Free of charge as he's staying here a couple of days a week while he working up here. He likes his baths and although the 12Kw Redring powerstream took a good 45 mins to fill the bath he wanted something "Up to the job".

I did get an unvented cylinder when i initially did my gas to electric conversion but its trying to find a qualified plumber to install it. I had a 100 litre one sat in the cellar for about 6 months. I could find plumbers who were qualified to install it but non of them kept appointments or were too busy so I put it back on ebay. Hence i went for the Powerstream, i know it is designed for a point of use heater but it supplied the house with hot water even though slow, for 2 years trouble free.

 

[Agile]

I did get an unvented cylinder when i initially did my gas to electric conversion but its trying to find a qualified plumber to install it.

"Keeping appointments" is often not possible for those who do repairs.

I know that there are some difficult people who expect us to come at a fixed time. Fixed time appointments are for people in offices and just talking to each other. Discussion can be ended at any time.

We dont just down tools at 1700 and go home. We cannot leave someone with no water supply or a faulty boiler. We carry on until the fault has been found and fixed.

I notice that British Gas have copied what we have always done of telephoning shortly before we are able to come.

Tony

 

[cider]

Mate who installed it has the Temperature Mixing Valve configuration wrong

 

[amtrakuk]

I did get an unvented cylinder when i initially did my gas to electric conversion but its trying to find a qualified plumber to install it.

"Keeping appointments" is often not possible for those who do repairs.

I know that there are some difficult people who expect us to come at a fixed time. Fixed time appointments are for people in offices and just talking to each other. Discussion can be ended at any time.

We dont just down tools at 1700 and go home. We cannot leave someone with no water supply or a faulty boiler. We carry on until the fault has been found and fixed.

I notice that British Gas have copied what we have always done of telephoning shortly before we are able to come.

Tony

yeah I understand that you can't just drop tools at a set time, a phone call would be useful even if to say they cant make it, only takes a couple of minutes max.

 

[amtrakuk]

Mate who installed it has the Temperature Mixing Valve configuration wrong

Seems like a problem has been identified. The rod thermostats seem to be faulty. Measuring the cylinder temperature, the bottom element is switching off at about 45 degrees and the top element was switching off at about 50, despite both being set to 70 degrees.

 

[Axel]

Must cost a few $ to heat electrically....