New Boiler to replace a old Worcester 35CDi II

[ShaunCorbs]

All looks good to me maybe there was a fault flow regulator inside the boiler as well causing too much flow through the plate compounded by the fault hw thermistor

Glad your happy and have a working boiler to correct spec 👍

 

[j3oeff]

If the hot & cold taps are the same size/type then one might expect the flowrates to be similar when fully opened so if you find the cold tap flowing 12 to 14 LPM (the hot is presently ~ 9LPM) then obvious throttling going on somewhere.
Some combi boilers have restrictors installed to limit the flowrate to give a dT of 35C through the boiler, a 30kw boiler will give a flowrate of 30*860/60/35,12.3LPM. with a temperature rise (dT) of 35C.

Cold water from bath tip is filling a 1 litre jug in around 2.10 seconds and it was consistent on about 6 fills.

 

[j3oeff]

All looks good to me maybe there was a fault flow regulator inside the boiler as well causing too much flow through the plate compounded by the fault hw thermistor

Glad your happy and have a working boiler to correct spec 👍

I am happy now yes. Just glad to finally have hot water and be able to take baths and also keeps the wife happy.

I will however have to investigate the shower further as there is an issue with that and the temperature not being correct .

 

[John.g]

That's some flow through the cold tap at 28.5LPM, the hot and cold pressures to any mixer should be more or less the same, I think within a 0.5 to 1bar of each other to get satisfactory mixing so possibly some problem with a PRV on the cold supply to the shower or whereever. . Probably have to get a plumber to investigate this.

 

[ShaunCorbs]

I am happy now yes. Just glad to finally have hot water and be able to take baths and also keeps the wife happy.

I will however have to investigate the shower further as there is an issue with that and the temperature not being correct .

Have you tried cleaning the filters/ strainer in the shower ?

 

[j3oeff]

Have you tried cleaning the filters/ strainer in the shower ?

It's a new shower head so shouldn't be the issue. The issue started with the old boiler where it was boiling hot even on 38c. Had to turn it right down to 25c and then it was ice cold so that's why I was thinking an issue with the tap itself?

 

[j3oeff]

That's some flow through the cold tap at 28.5LPM, the hot and cold pressures to any mixer should be more or less the same, I think within a 0.5 to 1bar of each other to get satisfactory mixing so possibly some problem with a PRV on the cold supply to the shower or whereever. . Probably have to get a plumber to investigate this.

It is abit odd. It was previously working fine months ago but as the old boiler deteriorated the shower temps started playing up and have continued with the new boiler.

 

[ShaunCorbs]

It's a new shower head so shouldn't be the issue. The issue started with the old boiler where it was boiling hot even on 38c. Had to turn it right down to 25c and then it was ice cold so that's why I was thinking an issue with the tap itself?

Yes sounds like the shower cartridge has gone

 

[John.g]

Shaun was referring to filters which may be installed where the mixer bar connects to the pipework but would require hot and cold water isolation somewhere.

Not sure, what this will prove, if anything, but maybe turn the shower temperature setting to max then reduce the Boiler DHW temp setting to 40Cish and monitor flow/temp.

 

[j3oeff]

Shaun was referring to filters which may be installed where the mixer bar connects to the pipework but would require hot and cold water isolation somewhere.

Not sure, what this will prove, if anything, but maybe turn the shower temperature setting to max then reduce the Boiler DHW temp setting to 40Cish and monitor flow/temp.

Will give that a go.

I assume I can isolate the water upstairs and then take the mixer tap apart to check filters etc and give it a clean/descale or replace.

 

[j3oeff]

Good morning guys,

I've noticed my pressure bar has gradually Been going from 1.5 to now sitting at 1 bar since it last lost pressure and I got the error.

Is this a cause for concern because I can see it coming up with the same error again in 2-3 days which makes me think I have an issue somewhere and I still think back to those radiator valves.

 

[ShaunCorbs]

If your pressure is dropping you may have a leak

 

[j3oeff]

If your pressure is dropping you may have a leak

Any idea how I can find out as I cannot see any visible signs or anything

 

[ShaunCorbs]

Over night can you close both 22mm valves eg first 22mm pipe either side flow and return over night

Make sure heating is off for this test

 

[j3oeff]

Over night can you close both 22mm valves eg first 22mm pipe either side flow and return over night

Make sure heating is off for this test

Although I'm learning and understanding things more I'm still not sure what valves you mean 😆

 

[ShaunCorbs]

The left and right ones eg white drain valve and the other one connected to the right if the filling loop

 

[ShaunCorbs]

The black valves on the big pipes

 

[j3oeff]

The black valves on the big pipes

Ok will that do tonight and see. What will it show me by the way or what am I looking out for come morning with both them closed?

We had heating on as normal yesterday and used hot water etc. Before we went to bed I took a picture of the boiler and where pressure was then again this morning when I got up. See attached.

 

[ShaunCorbs]

If it’s where it was after you closed the valves the leak is on the system but if it drops it’s the boiler

 

[j3oeff]

If it’s where it was after you closed the valves the leak is on the system but if it drops it’s the boiler

Ok pal nice one. Will check tonight and see. One thing I've just noticed when going to wash the cars is the outside tap is leaking by looks of it. I assume this wouldn't be the issue?

 

[ShaunCorbs]

No aslong as it’s the outside tap leaking and nothing above

 

[j3oeff]

No aslong as it’s the outside tap leaking and nothing above

No, deffo just the tap leaking around a join by the looks of it

 

[j3oeff]

So I shut off the valves last night and took a photo along with one this morning when I opened them back up.

 

[ShaunCorbs]

Before you opened the valves was the pressure the same as the first photo ?

 

[j3oeff]

No, I took the picture of it under 1.5 bar then opened valves. Nothing dropped or went up. Just stayed at below 1.5 as second picture

 

[ShaunCorbs]

Hmm strange

 

[j3oeff]

So does that not point towards a boiler issue? Or should i of done it a different way? In stages what i did....

1) Turned Valves off at 11PM
2) Took photo of pressure gauge
3) Took photo of pressure gauge at 7AM
4) Opened Valves back up and needle stayed in the same position.

 

[ShaunCorbs]

It points to no drop / leak

 

[j3oeff]

It points to no drop / leak

I thought....

If it’s where it was after you closed the valves the leak is on the system but if it drops it’s the boiler.

In my case, it's dropped from its original point last night so points to the boiler? Or am I reading it wrong?

 

[ShaunCorbs]

True but once the valves were open the pressure should rise I’m guessing the heating was still warm when you turned the valves off last night hence the 0.2 drop ?

 

[j3oeff]

True but once the valves were open the pressure should rise I’m guessing the heating was still warm when you turned the valves off last night hence the 0.2 drop ?

Yes, the heating went off around 10.15ish.

Let's say I do it again to be 100% sure.

If heating goes off at say 9pm? Take a pic and close valves at gone 11pm? Then in the morning open valves and then take a pic or take pic then open valve?

 

[j3oeff]

Seems there was a slight drop last night.

 

[ShaunCorbs]

And boiler was cold before pic was taken ?

 

[j3oeff]

And boiler was cold before pic was taken ?

Stone Cold! Heating had been off for 2 hours 20 minutes before the pic at gone 11PM.

 

[ShaunCorbs]

Is the prv dripping outside ?