Plumbing query

See attached picture.

Green arrow points to plumbing which I believe by passes the heater and returns to the pool.

Blue arrow is linked to the water going via the heater exchange

Red arrow is water coming from the filter and is returning to the pool.

Question;

When I want to heat I open the blue arrow valve. I leave the green arrow valve open as-well.

The pool does eventually heat up but I assume the water is being diverted mainly to the green arrow valve route as it is the lower of the two.

I was thinking to close off the green arrow valve, it should then flow all the water via the heater exchanger - blue arrow
Valve, right? This could heat the pool potentially 50% more quicker.

My concern is if the pressure is too much ... it will potentially damage something?
Should I keep an eye on the filter gauge in this case?

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What model heater do you have? How many BTUs?

Post pics showing all of your plumbing and the heater.
 
Yesterday at 7pm temp gauge was showing 15 degrees.
Switched on heater.
This morning at 7am it is showing 19 degrees.
Did not put solar cover on.
Weather over night was approx 8 degrees.

Heater exchange
On the spec picture I believe it is the last 4th one - 3705 / 10’000 gallons

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Your heater setup will raise your pool water by 1 degree an hour under optimal conditions.

45K liters of water is 100,000 lbs and your heater is 100,000 BTUs.

Without a solar cover your 12 hour temperature rise of 4 degrees on a cold night without a cover is to be expected. The rest was lost to heat loss by the pool to the air.
 
Il get the solar cover on - normally does be but I needed to give it a clean.

On the initial point though... should I close the valve indicated by the green arrow.... so that all the water flow is diverted via the heat exchange.

I still do not fully understand your system. I don’t see any reason not to experiment and see what effect it has.
 
That is real plumbing type of valve, not pool equipment stuff. That is when I call in a real plumber.

There is no good large size picture of the valve to see it clearly and what it is connected to.
 

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I have fixed the leak on the gate valve.

Back to original post. I believe I have found my answer via this article > What Is a Bypass Valve on a Swimming Pool Heater for?

Further down my question has been answered:

Bill Roberts.. to determine sufficient flow through the heater, this can be done using the filter pressure gauge. With a clean filter, bypass the heater completely and take note of the pressure. Then, change valve so that ALL flow is directed through the heater. If the pressure changes drastically then there is flow restriction. (it will change slightly with any heater) the pressure will be higher if filter is plumbed BEFORE the heater, or lower if after the heater. Remember though, during normal heater operation that the valve should be positioned to allow flow through both the heater and bypass. This allows for better flow with enough flow with enough water going through heater.
 
You have a hot water heat exchanger run by a boiler I'm guessing. Here in US you rarely see these systems. To experiment close off the bypass valve partially and see what effect it has overall. Depending on pipe size and pump flow you may be able to put all the flow thru the exchanger
 
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Yes, you are correct it is heated via the house gas boiler.

I have worked out it takes 12 turns to close off the by pass. I will do 3 turns at a time and see what effect it has on the pressure gauge on filter.

The pipework for heating is a raised loop from the initial return line, the water has to go up and over. When bypassing the heater the water drops down.

With both valves open I am guessing when the water is returning the natural flow is to follow the lowest point - so in this case the majority of the flow maybe bypassing the heater.

Blue is return going out to pool unheated
Red is water flow going via heater exchange

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Turned off the bypass so all water is flowed via heater - there was hardly any notice in pressure change on the filter gauge.

I have a tiny leak when the bypass is anything but open so will get this looked into.

another question:
Will the water flow speed going into the heat exchange have a serious effect on how the heating works? Will a slower flow have more value as it will pass through heat exchange slower to warm more? Faster flow will pass through quicker but will also sit in heat exchange quicker so less heat transfer.
 
Will the water flow speed going into the heat exchange have a serious effect on how the heating works? Will a slower flow have more value as it will pass through heat exchange slower to warm more? Faster flow will pass through quicker but will also sit in heat exchange quicker so less heat transfer.
The heat delivered to the pool is related to both temperature AND flow rate (heat transfer is proportional to dT * GPM - heat loss). Halving the flow rate doubles the heat gain in the heater (dT) but it also increases the heat loss to the environment. So it is more energy efficient to pass the water through the heater as quickly as possible.
 
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