Opinions please on this combi install? All ok? Pics attached

I have not read anything in the intermediate pages as I only came across this posting tonight.

The only point that i would make is that technically the condensate pipe should be insulated where its outside and should have a "fall" of perhaps 1:40 on the horizontal section.

The "fall" really looks stupid when its against brickwork but its what creates the flow of water along the pipe.

Tony
 
Gosh this thread got exciting overnight. :wink:

A couple of quick questions about how the Remeha actually runs, now that we are getting to know it...

i) It sometimes fires up at odd times, when the thermostat says the room is already at target temp, and when no DHW is being demanded. And the radiator without the TRV doesn't warm up. I had a look on the front panel at these times and it says "6". What is it doing, what is mode "6"? I can't see any mention of it in the user or installation manuals, or online.

ii) We've noticed that if we run the hot tap full (for a bath) the water isn't very hot, but if we run it more slowly it is scaldingly hot and we need to add plenty of cold (which is what we are used to). Should the tempreture of the DHW vary so much with flow rate? I had assumed that as the boiler has been told what temp to make the DHW that it would just deliver less flow to meet this temp? i.e. that if I put the hot tap on full the boiler would think "well I can't deliver DHW at the temp I have been told to at the maximum flow rate so I will deliver it to temp but at reduced flow rate". It's not a problem I guess but I just wondered if it's normal or if it can be changed?

Cheers,

Andy
 
Reading some of the posts all I can say is, people in glass houses should not throw stones.

There are guys here who I am certain produce work that is above average, even better than that. I am sure far better than I can produce. Then there are people who have jumped on the band wagon to pull this thread to pieces with perceived notion of how work should have been carried out.

Important things like complying with the Gas Safety Regs, condensate drain etc far outweigh the argument that the brickwork should have been better.

It is not unusual to see a boiler change carried out in four hours. Such jobs show up defects far worst than what is shown in the pictures. WRT the condensate termination- often it simply discharges onto the ground be it soil, concrete or monoblock; and forget the larger bore plastic- 0.75" all the way to clean the area where condensate hits the deck.

OP, job is not bad. Talk to the installer. Get him to check the hot water flow rate is as per the manual. It should say something like 15l of water at 35 degrees C temperature rise. Check cold water temp into boiler (say 5 degrees C), add 35 degrees to it. When boiler supplying 15l of water at the hot tap (tap fully open), hot water will be 40 degrees or more at the tap
 
DP - Thanks for that.

Anyone got any ideas on the mode "6" thing on the Remeha, it seems to be the only mode not mentioned in the manual. 0,1,2,3,4,5 and 7 are all listed but not 6? :?

I'm intrigued to know heh.

Andy
 
Hi Andy

The number 6 you are refering to is the pump overun mode the boiler is in at that particular time, it should be overunning at factory setting 2mins, but this could have been overidden by installer to run to 99!!!!

Only by getting into the installer settings will you find out.

Hope this helps
 
Gareth - Thanks for that, and welcome to the forums. First post I see. :)

What's the pump overrun mode for then, it seemed to fire up randomly at about 5am today? Would the pump overrun only occur after something else?

There was no DHW demand and the programmer is set very low overnight so it shouldn't have been DHW or CH making it fire up? :?

Andy
 
Hi Andy

The reason it is coming on ad hoc is due to it being set on comfort mode this ensures that you have hot water immediately you turn the tap on, basically it pre-heats the hot water before you draw it, this can also be disabled by pressing the R button once, then press the return button and hold for two seconds, this will bring up P1,use the + button to get to P4, this will probably show the number 0, you need to change this to number 2, you do this by pressing the return button once, change the setting to 2 by using the + button then press return again, this will log in the new parameter.

Easy peasy.

All the best

Gareth
 
Gareth - Thanks again, alas P4 is already set to 2. :?

I see position 1 is Eco mode, might that be worth a try? The user notes mention "external calorifiers" or some such as being bad things to have if it's set to Eco mode, I dunno if I have one of them, my guess would be not?

Andy
 
The boiler just did one of it's little random firings up. The room thermostat said it was an ok temp and no one turned a hot tap on.

It went 1, 2, 3 (indicating it was firing up for DHW).

Then it went back to 1 for about 15 seconds then it went to 6 for about 2 minutes.

If 6 is the pump overrun thing then that would bear out the 2 min thing as that is the default of P22 as you said but P22 says it is overun for CH not DHW? So how come it followed the boiler being on 3 (not 4)?

Could it be related to P26 (DHW cut in temp)? :?

It's not life or death I suppose but it seems silly for the boiler to be firing up if it doesn't need to be (i.e. when there is no CH or DHW demand).

Hang on just thinking for a moment, the rad in the upstairs bathroom used to be on the same circuit as the DHW (it used to warm up when there was a surplus of hot water). I told him about that before we went away, but if he had left that on the DHW circuit could that explain this behaviour? That when the rad in the upstairs bathroom (that now has a TRV) draws hot water it is making the boiler fire up in DHW mode?

Cheers,

Andy
 
ii) We've noticed that if we run the hot tap full (for a bath) the water isn't very hot, but if we run it more slowly it is scaldingly hot and we need to add plenty of cold (which is what we are used to). Should the tempreture of the DHW vary so much with flow rate? I had assumed that as the boiler has been told what temp to make the DHW that it would just deliver less flow to meet this temp? i.e. that if I put the hot tap on full the boiler would think "well I can't deliver DHW at the temp I have been told to at the maximum flow rate so I will deliver it to temp but at reduced flow rate". It's not a problem I guess but I just wondered if it's normal or if it can be changed?

Could be a problem, we have a Vaillant ecoTEC plus 937 (what a mouthful) and even when it is freezing outside you can get lovely hot water with the tap full open.
 

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