Ideal logic 30 combi. HW issue

[armyash]

Hi, tonight's job is as follows. Cust has just bought the house and not moved in yet, currently decorating.


Been to look at their ideal logic 30. Boiler in the kitchen. Shower is a thermostatic bar. Water runs Luke warm. Basin runs a bit better but runs cooler the higher the flow. Bath hot tap is the same if I turn the flow down the water runs hotter. ( the tap itself seems in need of a repair as the water either dribbles out or shoots out, I think the valve needs greasing and new washer)


kitchen hot runs much better but only 1m from the boiler but then in full flow it runs lukewarm. Normally I would go straight for the hex but the boiler was serviced in September, the notes on the service record say 'leak on hex, needs replacing'.


The boiler was still under warranty at the time and apparently Ideal went out in November and changed numerous parts including the hex but there is no proof of this. The cust has a document from solicitor showing this info but have been advised they have to contact ideal for confirmation this part has been changed at a cost of £20 which they are doing tomorrow.


The problem is just because the ideal engineer might have said he changed the hex doesn't mean he did. The boiler is reasonably new so it's not as though I can look at the hex and see if it looks new or not.


If it's not the plate, what else could it be?


Thanks

 

[townfanjon]

Usual HW problem on these is the turbine , cover off run a hot tap , the sensor should show a solid red light , not expensive, easy to change but check it first

 

[armyash]

Usual HW problem on these is the turbine , cover off run a hot tap , the sensor should show a solid red light , not expensive, easy to change but check it first

Thanks will go back up tomorrow night and check that.

The hex gets extremely hot if it makes any difference, too hot to touch for more than a couple of seconds.

 

[oz-plumber]

Do those units have a water temperature sensor ( plunge sensor / thermister )

Should be screwed into or clamped onto hot water pipe with a couple of wires connected to it.

What your describing fits the bill with a faulty sensor

 

[oz-plumber]

Do those units have a water temperature sensor ( plunge sensor / thermister )

Should be screwed into or clamped onto hot water pipe with a couple of wires connected to it.

What your describing fits the bill with a faulty sensor

 

[Stanios]

Does it cycle on hot water? Also whats the gas supply like?

 

[armyash]

Boiler stays alight on hw, temp is stable so long as taps are not run on full flow.

Back tonight as was short of time last night will check everything over and update.

 

[hammers4spanner]

get rid of it put a decent boiler in sick of the sight of these this winter.

 

[newcastle phill]

Not the answer hammers lol

 

[armyash]

For anyone interested.

Solid red light on flow turbine.

Removed plate and cleaned out with descaling chemical. Got a bit of debris out but not the worst I've seen.

Replaced plate and tested. Kitchen hot tap runs extremely hot at about 75% flow, if I increase to max it runs lukewarm. Cuts can live with this.

Basin upstairs, hot water temperature is reached, then it dips out then it will reach temperature again, gets very hot. It will run fine at about 75% again.

I had to repair the bath hot tap (grease and new washer). The bath hot tap seems to be running fine, no issues.

Thermostatic bar shower, the pressure on when this is used is extremely high, much higher than the taps. If it's run on max temp at about 60/70% it's perfect but if you increase the flow/pressure it will cool down. I said they could do with replacing it, it seems to make a strange noise intermittently. I have told them to see how things go when they move in.

When the hot water is running the return pipe also gets hot, about 10mm down from the return service valve, it's not going far.

There us no hw sensor, the hw works off the return sensor.

Is there anything else that could be causing this to run intermittently?

 

[armyash]

For anyone interested.

Solid red light on flow turbine.

Removed plate and cleaned out with descaling chemical. Got a bit of debris out but not the worst I've seen.

Replaced plate and tested. Kitchen hot tap runs extremely hot at about 75% flow, if I increase to max it runs lukewarm. Cuts can live with this.

Basin upstairs, hot water temperature is reached, then it dips out then it will reach temperature again, gets very hot. It will run fine at about 75% again.

I had to repair the bath hot tap (grease and new washer). The bath hot tap seems to be running fine, no issues.

Thermostatic bar shower, the pressure on when this is used is extremely high, much higher than the taps. If it's run on max temp at about 60/70% it's perfect but if you increase the flow/pressure it will cool down. I said they could do with replacing it, it seems to make a strange noise intermittently. I have told them to see how things go when they move in.

When the hot water is running the return pipe also gets hot, about 10mm down from the return service valve, it's not going far.

There us no hw sensor, the hw works off the return sensor.

Is there anything else that could be causing this to run intermittently?

 

[newcastle phill]

So you have a solid red light on the hall sensor all of the time during hot water. Amd you have good flow from the tap ?
Have you taken the turbine out and cleaned it.
Also have you cleaned the flow regulator and filter ?

Both thermistors should be
At 60 degrees"ish 2500ohm
at 85 degreesish 1000ohm

If they are wildly different then replace.

And at 75% tap opening its gas rating fine. And with the hot tap wide open its still gas rating fine - no drop off ?

Only other thing is tap max flow is more than the boiler can heat

 

[Stanios]

what descaler did you use? only real strong acid gets rid of all the crap i.e sulphuric
sounds like the plate is just blocked

 

[ShaunCorbs]

I would say more flow than the boiler can cope with

What kw rating is it ash ?

 

[Stanios]

I would say more flow than the boiler can cope with

What kw rating is it ash ?

Its 30 per thread title

 

[townfanjon]

Have you tried a flowcup ash to see if its as per manufacturer flowrate .

 

[armyash]

So you have a solid red light on the hall sensor all of the time during hot water. Amd you have good flow from the tap ?
Have you taken the turbine out and cleaned it.
Also have you cleaned the flow regulator and filter ?

Both thermistors should be
At 60 degrees"ish 2500ohm
at 85 degreesish 1000ohm

If they are wildly different then replace.

And at 75% tap opening its gas rating fine. And with the hot tap wide open its still gas rating fine - no drop off ?

Only other thing is tap max flow is more than the boiler can heat

Thanks.

Yes solid red light.

Turbine has been cleaned, it's brand new.

Didn't do the regulator.

Where do you get the info to test the thermistors?

It was working a lot better last night when I finished and once the temperature was reached it was staying there. Unless on 100% flow.

 

[armyash]

what descaler did you use? only real strong acid gets rid of all the crap i.e sulphuric
sounds like the plate is just blocked

Hi I used fx2, I got some debris out but not a lot. It's a new plate.

 

[mfgs]

Have you tried a flowcup ash to see if its as per manufacturer flowrate .

This is the only way of determining whether the boiler is working as per the spec. The cold incoming water temp in the winter makes the hot water cooler. Check the manual for what temperature rise you should be getting at what flow rate, so like 11 l/min at 35 degree temp rise. The incoming main will be about 10 degrees roughly at this time of year so with a flow of 11l/min you should see a water temp of 45 degrees as an example.

 

[mfgs]

Have you tried a flowcup ash to see if its as per manufacturer flowrate .

This is the only way of determining whether the boiler is working as per the spec. The cold incoming water temp in the winter makes the hot water cooler. Check the manual for what temperature rise you should be getting at what flow rate, so like 11 l/min at 35 degree temp rise. The incoming main will be about 10 degrees roughly at this time of year so with a flow of 11l/min you should see a water temp of 45 degrees as an example.

 

[armyash]

This is the only way of determining whether the boiler is working as per the spec. The cold incoming water temp in the winter makes the hot water cooler. Check the manual for what temperature rise you should be getting at what flow rate, so like 11 l/min at 35 degree temp rise. The incoming main will be about 10 degrees roughly at this time of year so with a flow of 11l/min you should see a water temp of 45 degrees as an example.

I just had another look at the manual.


It says dhw flow rate is 12.4. If the flow rate is over this, it will affect the operation in hw mode?

Is this what you mean?

 

[mfgs]

Exactly, if the flow is higher then the temperature rise will be less resulting in lower temperature water. Manufacturers normally quote either a 35 or 40 degree temp rise.

Get your flow cup and digital thermometer out to confirm.

 

[mfgs]

Exactly, if the flow is higher then the temperature rise will be less resulting in lower temperature water. Manufacturers normally quote either a 35 or 40 degree temp rise.

Get your flow cup and digital thermometer out to confirm.

 

[armyash]

Exactly, if the flow is higher then the temperature rise will be less resulting in lower temperature water. Manufacturers normally quote either a 35 or 40 degree temp rise.

Get your flow cup and digital thermometer out to confirm.

Ok thanks that makes it easier to understand.

If the flow is too high for the boiler what is the best solution, would it be higher kW boiler or is there a cheaper, easier option.

 

[armyash]

Exactly, if the flow is higher then the temperature rise will be less resulting in lower temperature water. Manufacturers normally quote either a 35 or 40 degree temp rise.

Get your flow cup and digital thermometer out to confirm.

Ok thanks that makes it easier to understand.

If the flow is too high for the boiler what is the best solution, would it be higher kW boiler or is there a cheaper, easier option.

 

[newcastle phill]

Turn the cw inlet down til flow is reduced to what boiler can cope with. May increase water noise slightly

 

[mfgs]

As above, easiest way is to restrict the flow going into the boiler or alternatively just advise the customer on the limitations of their boiler. Understanding how it works will enable them to get water at the temperature they desire.

 

[armyash]

As above, easiest way is to restrict the flow going into the boiler or alternatively just advise the customer on the limitations of their boiler. Understanding how it works will enable them to get water at the temperature they desire.

I actually tried that last night, I also restricted the flow on the basin hot at the ISO but due to the noise I opened it up again. Thanks for the info.

 

[armyash]

As above, easiest way is to restrict the flow going into the boiler or alternatively just advise the customer on the limitations of their boiler. Understanding how it works will enable them to get water at the temperature they desire.

I actually tried that last night, I also restricted the flow on the basin hot at the ISO but due to the noise I opened it up again. Thanks for the info.

 

[armyash]

http://www.ukplumbersforums.co.uk/plumbing-forum/95568-hot-water-still-running-when-boiler.html

Having a nose at other threads and came across this one. Does anyone think this is similar to the issue I'm having?

 

[armyash]

Update. Cust happy, now all working.

Thanks for the replies.

 

[mfgs]

So what was it?

 

[armyash]

Debris build up in the plate.

Cust said now all working fine, I told them to let me know if it changes and I'd have another look.