UFH Stone cold

[Cold fish]

Hello, just bought a new house in December, UFH gas boiler on ground floor. Open plan living area. Thermostat set on max (26), room temp is 16. Just paid extra £500 for extra accelerator pump. Still floor is stone cold, except one third of kitchen floor. Previous owners had system flushed 6 months ago. Any suggestions would be much appreciated, is ruining life in the
new house as can't sit downstairs !

 

[snowhead]

How old is the house?
Was the U-F fitted when the house was built?
If not how old is U-F?

Where was this expensive pump fitted?

 

[SimonG]

Airlock?

 

[kozak1968]

Zone valve could be faulty if one is fitted. If its a Honeywell it can be manually opened. Also check pump is spinning.

 

[Cold fish]

Hello, thanks for your replies. House is 15 years old. Suppose UFH was installed at that time. New pump is a grundfos pump. Temp gauge on manifold says 40, the return is 30.

 

[MRDrip]

Do you have details of the "extra accelerator pump" and where it's been fitted.

 

[Cold fish]

I am no expert, could not really explain technically. It is just next to all the blue pipes that go off into the living room etc. I can hear it is working but does not feel boiling hot. Plumber said it would definitely solve the cold problem but 24 hours later still 16 degrees.

 

[kozak1968]

40 flow 30 return sounds about right. It takes time to heat up.

 

[Cold fish]

I live in hope.....can't wait for the summer as feeling obsessed about how cold it is. Shame can't just put radiators instead.

 

[kozak1968]

Also sounds like air lock on one of the circuits as mentioned before. How many pipes on the manifold ?

 

[Cold fish]

7 going out and 14 coming back, is that right?. Plus the 1 pipe going upstairs to the playroom where UFH works well (just as well really)

 

[migoplumber]

under floor heating probs are always a pain because it takes so long to notice any changes you have applied (3 hrs typically)
take a picture of your blue pipes and what they are connected to.
there are so many possible causes. if there are many pipes connected to a manifold system, with a bypass to the return, thats where you could get your 40/30 from with a bit of latent heat getting into the floor.
if you have little actuators (small plastic things with wires going to them) on top of your blue pipes that are not working, you may have an electrical issue.
you could remove one of these actuators from the manifold ( they unscrew ) and watch what happens.
all though dont let the temperature into the manifold go above 55.
good luck

 

[Cold fish]

Does this work?

 

[snowhead]

That's 7 out , 7 back

 

[kozak1968]

Best to get a good plumber in to check the manifold and system, you could unbalance the system by opening and closing valves.

 

[Cold fish]

It is upside down. Some going out have little red caps, some don't. Silver pipe leads to where he has put the extra pump.

 

[Dannypipe]

I am no expert, could not really explain technically. It is just next to all the blue pipes that go off into the living room etc. I can hear it is working but does not feel boiling hot. Plumber said it would definitely solve the cold problem but 24 hours later still 16 degrees.

Have you tried calling the plumber up and telling him that the pump hasn't done the trick? He may have missed something. Dodgy actuators, or an airlock.

You say one circuit is working, which could account for your 40Flow and 30 Return. The other circuits might be stone cold simply as they're airlocked.

I'd call the plumber back.

 

[snowhead]

They are manually balanced zones, not individually controlled as would be done nowadays.
Has the whole system been balanced recently?

Each zone needs disconnecting and proving good flow thro' it.

 

[migoplumber]

so the white heads on the bottom manifold control the on off to each individual zone.
cant see any wires going into them tho. so your stat could be controlling a motorized valve. but that would be an unusual set up. generally each individual room stat would be connected to one of them white actuators.
cant see the pump on system. and there is no bypass shown, so something amiss.
unscrew/take off the white caps and see what happens. you should have a flow into the floor

 

[Cold fish]

Thanks, I will do Monday morning. Just worried i bought a house with a dodgy heating system. Thanks for all your tips. Have a nice weekend.