Ideal Isar taking longer to heat up DHW

[dereknoble]

Hi,

I have an Ideal Isar M30100 combi boiler (about 7 years old) and it always used to take about 10-20 seconds to heat the DHW up to scalding temperature.
Now, it takes at least 10 minutes to heat the water up and even then its not as hot as it used to be.

I have called Ideal and they told me it is either? (please excuse the layman's descriptions)

either:
the link between the DHW and central heating
The input or output thermister
the DHW plate heat exchanger.

From experience what is the most likely (or usual) reason for this? I have a DHW plate heat exchanger that I can put in (or get someone to put in rather).

thanks in advance,

Derek

 

[engineerman]

they are telling you its the diverter,plate or dhw thermister,call out a decent engineer who will diagnose and fix the fault instead of guessing what parts to chuck at it

 

[superman123]

dhw plate to plate heat exchanger is blocked, hope you have new washers with your new one. dont try to doit your self gassafe web you can find a local engineer.

 

[dereknoble]

they are telling you its the diverter,plate or dhw thermister,call out a decent engineer who will diagnose and fix the fault instead of guessing what parts to chuck at it

Well, if I knew a decent engineer then I would always call him/her but how do you know who is decent without personal recommendations. I don't know anyone near me.
Also, its difficult to find an engineer that will take on any job where I live. The last time my heating failed it was winter and I called 5 engineers and 4 of them said they didn't want the job and the one that did told me 3 weeks before he could visit. So, I said sod it and fixed it myself. After phoning Ideal Boilers I worked out it was the DHW plate heat exchanger that needed replacing so I read the installation manual and did it myself. It was easy enough once I knew what it was but admittedly it was probably the easiest job to do on one of these things.
I've now got one of those insurances to cover faults but they don't cover pre-existing issues so I just want to get this one thing sorted before they do their first service.

 

[dereknoble]

dhw plate to plate heat exchanger is blocked, hope you have new washers with your new one. dont try to doit your self gassafe web you can find a local engineer.

Thanks for the advice.
I don't know if this changes your advice but when the DHW is on to fill the kitchen sink the radiators start to get warm.
I have a spare DHW plate heat exchanger that I can install (done this before, easy on this model).

 

[45yearsagasman]

If the rads heat on hot water then your diverter is passing. There is a new internal cartridge available as a spare. Not hard to do but depends on your skill level and confidence. There were 2 different diverter types. If you've done a plate before then the cartridge should be manageable.

 

[dereknoble]

If the rads heat on hot water then your diverter is passing. There is a new internal cartridge available as a spare. Not hard to do but depends on your skill level and confidence. There were 2 different diverter types. If you've done a plate before then the cartridge should be manageable.

Thanks for the advice.
How would I know which cartridge to buy?
On the ideal website it shows only one type but has a restriction underneath the description:
DIVERTOR VALVE CARTRIDGE KIT
- For use with H'Well VC6012 ('Grey Box' Div Head) only.

I dont know what a H'Well VC6012 ('Grey Box' Div Head) is??

 

[45yearsagasman]

The manual shows how to remove the head. Do that and the head model number will be on the data plate. I may be wrong in saying there were 2 different cartridges for your model. The later models differed. Just had a look myself and it shows only the one diverter.

 

[engineerman]

173624 is the part number for the grey headed diverter valve kit
phone ideal give them your boiler details and they will tell you the correct part number