Ideal miniHE - DHW excessive temp on primary circuit (lights) after plumbing work....

[capitanpugwash]

Hi all

Can anyone help?

My boiler: Ideal C24/C28 mini HE. 3 years old. Draining the system down to add the rad, the water was nice and clear though we are in a hard water area.

3/4 days ago a gas safe plumber extended my gas feed to my kitchen for a new range and extended the central heating circuit by one rad. He finished up testing the tightness and system and all seemed well.

However the DHW now comes out hot (as normal) for a short while (10 secs or so) before a ticking noise, then strange almost whimpering noise from the boiler, before the normal operation lights change to indicate:

"DHW operation
Excessive temperature on primary circuit" (from the servicing brochure)

It then cools down to luke warm for a short while before heating up again to boiling hot and then overheating again. The central heating works perfectly well.

I have measured the flow and get:

Cold tap - 12 litres/min
Hot tap - 6 litres/min which is obviously a lot less than normal.

I am guessing that there is some kind of restriction in the DHW inlet filter having worked through the fault finding section. Having said this there are obviously many parts of this that I cannot do properly. 😱

Does anyone have any other ideas? It is obviously Sat night and I'll be unable to get the plumber back until at least Monday. I am a competent DIY'er but wouldn't really want to touch a gas boiler for obvious reasons. My lodger would like a hot shower- does anyone have any ideas- except for sending her down to the local swimming baths 😛

Any ideas/fixes? It seems strange that having had 2-3 years of faultless behaviour from the boiler, that the plumber having cut off the gas and drained the system before recharging it could have coincided with the arrival of this fault.... 😕

 

[ecowarm]

Re: Ideal miniHE - DHW excessive temp on primary circuit (lights) after plumbing work

was the water supply stop tap turned off ? check to see if fully open

 

[capitanpugwash]

Re: Ideal miniHE - DHW excessive temp on primary circuit (lights) after plumbing work

Hi Ecowarm,

Sorry should have included that. It was not turned off and is still giving good pressure. The boiler itself is making a funny noise that is not qutie normal either.

 

[moony]

Re: Ideal miniHE - DHW excessive temp on primary circuit (lights) after plumbing work

was the gas pipe sizing done correctly is cooker running when boiler running?

 

[capitanpugwash]

Re: Ideal miniHE - DHW excessive temp on primary circuit (lights) after plumbing work

Yep. He ran the cooker in 22mm from main. He was keen to do in 22 mm even though he said it would work in 15mm in case we upgraded the range size later. He installed the boiler originally.

 

[Billy Bob Bob]

Re: Ideal miniHE - DHW excessive temp on primary circuit (lights) after plumbing work

sounds to me if your issues are unrelated to the works you have either a faulty dhw ntc,plate heat exchanger,air switch or a diverter valve dumping down

 

[moony]

Re: Ideal miniHE - DHW excessive temp on primary circuit (lights) after plumbing work

yep agree with gas man - looks like hes done his bit right matey - so would be looking into the boiler now for faults.