Cold then Hot then cold then hot ????? (1 Viewer)

Apr 27, 2008
11,788
13,942
Eastbourne East Sussex
Funster No
2,327
MH
Hymer low profile
Exp
Since 1972
My cold water to the shower runs intermittently hot when first turned on but only when the hot air heating is on. This id ue to the pipes for air and water running close together and the cold pipes being heated by the heating pipes. Running the cold for a few seconds fixes it.
 
Jul 6, 2016
1,547
1,264
West Sussex
Funster No
43,954
MH
Carthago Chic A clas
Exp
Since 1990
Here is an extract from the Truma Combi Installation Instructions:

When using pressure pumps with a high switching hysteresis,
hot water can flow back via the cold water tap. We recom-
mend installing a non-return valve between the outlet to the cold water tap and safety/drain valve as a return flow inhibitor. Observe the direction of flow when installing the non-return valve. (See figure 15 – Example of an installation with flexible hoses Ø 10 mm).

It would be interesting to know whether the OP @chippy63 eventually resolved his problem.
 
OP
OP
C
Aug 19, 2007
560
242
Birmingham
Funster No
120
MH
looking
Exp
2001
Here is an extract from the Truma Combi Installation Instructions:

When using pressure pumps with a high switching hysteresis,
hot water can flow back via the cold water tap. We recom-
mend installing a non-return valve between the outlet to the cold water tap and safety/drain valve as a return flow inhibitor. Observe the direction of flow when installing the non-return valve. (See figure 15 – Example of an installation with flexible hoses Ø 10 mm).

It would be interesting to know whether the OP @chippy63 eventually resolved his problem.


Well its funny you should bring this up as the answer is sort of but no !!!!, I took it back to the dealer, who put a non return valve in the easiest place to access he could, which solved the hot then cold issue but caused a pulsing flow problem instead ??????????.

We still have the pulsing problem :eek: ,We just got on an accepted the problem the rest of the year & i intend to see what i can do , in prep for use at beginning of march.

Karl

Subscribers  do not see these advertisements

 
Jun 29, 2015
3,428
56,430
Southampton
Funster No
36,999
MH
caravan (for now)
Exp
on and off since 1984
There is an adjustment screw on the pump. which may help with the pulsating flow
 

Rapido8066

Free Member
Aug 29, 2022
2
3
Funster No
90,951
MH
Rapido
I have same problem in my Rapido 8066, made in 2016, and been trying to find a solution for a long time so pleased to see the last post which shows that Truma suggest a non return valve should be fitted - so why did Rapido not fit one??
I will take this up with my Rapido dealer when I take the 8066 to them for the habitation check and ask them to fit the NR valve.
There will still be some warming of the cold water because the hot and cold pipework runs from the Truma bunched together with no insulation to prevent the hot pipe warming the cold, and vice versa!

Subscribers  do not see these advertisements

 
Feb 21, 2016
4,910
29,131
Uk
Funster No
41,726
MH
C class
Exp
Since 2017
I have same problem in my Rapido 8066, made in 2016, and been trying to find a solution for a long time so pleased to see the last post which shows that Truma suggest a non return valve should be fitted - so why did Rapido not fit one??
I will take this up with my Rapido dealer when I take the 8066 to them for the habitation check and ask them to fit the NR valve.
There will still be some warming of the cold water because the hot and cold pipework runs from the Truma bunched together with no insulation to prevent the hot pipe warming the cold, and vice versa!
You could ask chippy63 how he got on with his problem in 2019. Presumably it’s sorted by now!
 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Funsters who are viewing this thread

Back
Top