Heatline C28 - Intermittent DHW

[diyphildiy]

All,

I recently moved into a house with a Heatline C28 boiler, which was installed by a CORGI registered plumber(I have the certificate) before I moved in and worked perfectly until recently. The boiler is now just over 2 years old.

Although the CH continues to work perfectly, I am now only getting an intermittent response from the DHW. If I turn on a hot water tap, the boiler fires and begins to heat the water, but cuts out after about 60 seconds. By this time the DHW has heated to around 50 degrees. If I continue to run the hot water it cools down over the next 60 seconds until the LEDs on the boiler indicate a temperature of 30 degrees.

If I leave the DHW running this cycle continues - i.e. the boiler turns itself on and off around every 60 seconds, whilst the temperature of the DHW oscillates between 50/30 degrees.

Having had a look at the schematics in the technical documentation, I suspect a problem with the DHW Flow Sensor, but would be grateful of any advice.

Thanks,

 

[mehran]

i doubt it is the flow sensor

sound like a classic case of blocked plate heat exchanger

basically the most likely cause of your promblem is that the plate heat exchanger is blocked with crap. best bet is to get a competent corgi reg heating engineer to have a look at your boiler. you could also phone heatline up and ask the price for a repair.

if it is blocked then you need your system cleaned. if you lived close to me i could do as i have box full of heat exchangers

 

[diyphildiy]

Ahhh OK, that makes sense.

I'm guessing its gotta be the secondary heat exchanger as the CH continues to work OK? Is replacing this a big job?

I'm no expert, just curious.

Thanks,

 

[mehran]

yeh, easy if you know the best way to get to it , a pain if you don't

 

[Agile]

Thats one of those questions without any answer!

The easyiest way is by removing the gas valve which is a CORGI job!

Very occasionally you can remove it by disconnecting a pipe underneath, the DHW in is often the best and then slide it down the back!

We charge £106 to replace with a recon unit in our local area. Thats a quarter of the cost of the boiler. But then it was installed on the cheap and the installer did not bother to power flush the system.

Its about time someone took one of those cowboy installers to court!

Tony

 

[Deleted member 105431]

i doubt it is the flow sensor

sound like a classic case of blocked plate heat exchanger

basically the most likely cause of your promblem is that the plate heat exchanger is blocked with rubbish. best bet is to get a competent corgi reg heating engineer to have a look at your boiler. you could also phone heatline up and ask the price for a repair.

if it is blocked then you need your system cleaned. if you lived close to me i could do as i have box full of heat exchangers

remember the thread where I said the heatlines often play up after 2 years mehran?

 

[Slugbabydotcom]

If I leave the DHW running this cycle continues - i.e. the boiler turns itself on and off around every 60 seconds, whilst the temperature of the DHW oscillates between 50/30 degrees.

I'd be checking thermistors first !

 

[mehran]

Might last two years if your lucky before a major repair.

yes I do remember

love how a blocked heat exchanger would be heatlines fault. even if it was a dodgy ntc it would hardly fall in to the "major repair" category ...now a dodgy seal on the other hand that could put life and property in danger is a "major repair"

 

[Deleted member 105431]

Might last two years if your lucky before a major repair.

yes I do remember

love how a blocked heat exchanger would be heatlines fault. even if it was a dodgy ntc it would hardly fall in to the "major repair" category ...now a dodgy seal on the other hand that could put life and property in danger is a "major repair"

It may not be a blocked plate (although likely) and if it is then that is due to the poor installation (typical of all boilers sold in b&q). Both points I made last time too. A door seal hardly puts life and property at risk, the boiler will simply shut down. Almost all are changed now free of charge, and the new seals are much improved.

 

[mehran]

i am sure the boiler would shut down after it as mangled the inside of the boiler

so the risk of fire or co poisoning is not be big deal to you?

i know valliant are trying to play it down but come but bloody hell

if the main thing you have against heatline is that some of the installers that fit them then you don't have much of a case. heatline have flaws, pull them up on them and not the average standard of installers in this country.

anyway you should not beat up on the ugly step kid, it's all part of the valliant family now. heatlines flaws now belong to valliant to deal with

 

[Deleted member 105431]

i am sure the boiler would shut down after it as mangled the inside of the boiler

so the risk of fire or co poisoning is not be big deal to you?

i know valliant are trying to play it down but come but b****y hell

if the main thing you have against heatline is that some of the installers that fit them then you don't have much of a case. heatline have flaws, pull them up on them and not the average standard of installers in this country.

anyway you should not beat up on the ugly step kid, it's all part of the valliant family now. heatlines flaws now belong to valliant to deal with

I don't have a problem with Heatline, but you can't honestly say they are as good as their more expensive counterparts imo. You're obviously very loyal to them and I don't blame you but I personally wouldn't want one.

 

[mehran]

ok, they are not as good as some boiler makes and in places the cost cutting shows(like the clock) but they are amazing value for money and the after sales care is great.

ok... i put my hands up, I am brain washed

btw we fit viessmann boilers as well and a few biasi's

 

[Deleted member 105431]

ok, they are not as good as some boiler makes and in places the cost cutting shows(like the clock) but they are amazing value for money and the after sales care is great.

ok... i put my hands up, I am brain washed

btw we fit viessmann boilers as well and a few biasi's

Great value I'd agree with, can I ask what you think of the viessmans? Do you think they are worth the extra ££££ over Heatline?

 

[mehran]

i had a rush of installs when the old 100's where going cheap they are ok. the old 100 had a crap control panel and cost cutting showed... but if i had to fit a boiler with all the bells and whistles i would get the 200w

the new heatlines have took some design ideas from viessmann

are viessmann worth the extra £££? i fitted a viessmann for our best customer so yeah if they have the cash to spend we want to reward her loyalty with longest warranty we could get for her.

90% of the time it is a solaris

 

[diyphildiy]

Gents,

Thanks for all your replies so far. It would seem that some of you have your doubts about Heatline boilers in general, but I'm just trying to get to the bottom of whats going on before commiting myself to a large bill. I'm by no means an expert, nor am I about to start taking the boiler to pieces, but you continued advice/opinions are definitely appreciated.

One suggestion was the DHW thermocouple, so I disconnected it, but the oscillating DHW temperature I described earlier still continues. I've now re-connected it.

My initial suggestion that the flow sensor might be the problem was discarded (and I'm happy with that), so I'm warming to the idea that its the secondary heat exchanger. Before I go about getting an engineer round to look at/replace it, I was thinking of running some 'sludge remover' through the system.

What are your opinions of how effective this stuff is?

Thanks for your continued advice.