2 zone under floor heating. Does the pump need to be fitted to manifold

[Dharlen]

This is my first post and need help with underfloor heating.

I have just had an extension built with the floor area for this room now circa 24m2. This room is going to run underfloor heating on its own zone. Rest of the house is rads.

System has been installed and just waiting for room stats to arrive so insulation can be completed.

After the plumber left I had a look at the manifold and noticed that the pump hasn't been fitted. He informed me that he did this as he didn't want to cause pressure issues on my existing combI. 28I junior. I sort of understand this and wasnt worried. But having had another look I have noticed he hasn't fitted the mixer value which I assume is a big issue.

Any advice on how to proceed? I don't want to damage the boiler but I also don't want to be over heating my floor and damaging screed and tiles.

Many thanks in advance

 

[ShaunCorbs]

no needs a pump and blending valve

 

[townfanjon]

Surely he will fit them later ?

 

[Dharlen]

Thank you for the quick response.

Is there any chance that the additional pump will cause a problem with my boiler. Plumbers says he has had experience of this in the past and that my boiler is powerful enough with out additional pump being installed

 

[Dharlen]

I don't think he is planning on fitting later. Pipework and zone valves all fitted all the way back to the boiler. UFH is not running yet. I assume the zone valve is closed.

 

[ShaunCorbs]

can you take a pic of where the pipes come to?

 

[Dharlen]

At the manifold?

 

[ShaunCorbs]

At the manifold?

yes

 

[Dharlen]

As you will see its also leaking

 

[SimonG]

Oh dear. Get him back, you need a pump and mixing valve. Your combi pump wont push the water through, which is just as well as if it did it would overheat your floor.

 

[Tjdservices]

View attachment 24176

As you will see its also leaking

That is awful, as has been said, blending valve and pump needed

 

[Tjdservices]

Also an automatic air vent wouldn't go amiss, whoever installed this doesn't understand underfloor heating design

 

[Dharlen]

Also an automatic air vent wouldn't go amiss, whoever installed this doesn't understand underfloor heating design

What does an automatic air vent look like?

 

[Tjdservices]

Just google automatic air vent and they'll come up

 

[ShaunCorbs]

you dont need to look at a pic unless you have done it your self either get the original installer back or get a new qualified one

 

[Dharlen]

He is a sub contractor to my main builder and is coming back tomorrow. I will talk to him then.

Good job I noticed something was missing.

 

[PlumbBobBob]

is he actually a plumber or just another builder?

 

[Chalked]

Without a mixing valve and seperate pump. Your floor is going to get very hot! The only way this could work ( sort of) is if this was the only heating needed from the boiler. Then the boiler thermostat could be set at a lower temp.
But as you have existing radiators, you will need them to be higher temp.
It's a shame in our trade when the customer has to correct the plumber! In this case I do wonder if he is one.

Get him back and sort those leaks.

 

[Tjdservices]

He is a sub contractor to my main builder and is coming back tomorrow. I will talk to him then.

Good job I noticed something was missing.

So what was the explanation?

 

[Toddyplumb]

Have seen this a few times , people do not understand how underfloor heating works . Worst one we saw 2 manifolds 12 zones on one and 10 on the other all from a Baxi 100 combi . Took the customer 12 months to realise something wasn't right

 

[Dharlen]

Time for an update.
Plumber has fitted blending valve and manifold as instructed. Also two programmable room stats. One in the kitchen, where the underfloor heating is. The other in the lounge controlling the rest of the house radiators.
Both stats call heat and fire up the boiler. which is great. Was happy with the system until i checked this morning.
I have noticed that the pump is not live. Not wired to anything. I thought this may have been fine as boiler has capacity to run entire system. But im now concerned that when the blending valve closes, effectively cutting off the boiler, that there is nothing to make the water flow around the underfloor heating pipes. Is this assumption correct?

 

[jonnyswamp]

I doubt there's a cable from clock/stat to the manifold position to energise pump, but it should be wired
Does it work at all like it is?

 

[Unregistered]

Both zones work. But I have current set the blending valve to 30degree for initial set up. I plan to turn this up each day until i reach 40 degrees. So because of this low temp the valve is closed a lot.
The pump does nothing. No power or cables of any kind. Just being used as a expensive piece of pipe.

 

[Tjdservices]

Pump needs to be running, without circulation in the ufh it won't heat up, at present it is just running on the boiler pump, which is not designed to run ufh systems. so once that has shut down it won't circulate. The pump is there to circulate the water around the ufh to the blending valve temp. So the boiler will not be running all the time but the ufh pump will be running to keep the water flowing through the ufh pipe work. flow through the unwired pump will be minimal, The person doing this install really doesn't know what they are doing. I hope they havent also been involved with the boiler as alarm bells would be ringing.

 

[Dharlen]

Thats what I thought.
What should the pump be wired too? what tells it to pump?